diff --git a/java/com/google/gerrit/plugins/checks/Check.java b/java/com/google/gerrit/plugins/checks/Check.java
index bd46191..30bfa41 100644
--- a/java/com/google/gerrit/plugins/checks/Check.java
+++ b/java/com/google/gerrit/plugins/checks/Check.java
@@ -37,6 +37,9 @@
   /** State that this check is in. */
   public abstract CheckState state();
 
+  /** Short message explaining the check state. */
+  public abstract Optional<String> message();
+
   /** Fully qualified URL to detailed result on the Checker's service. */
   public abstract Optional<String> url();
 
@@ -64,6 +67,8 @@
 
     public abstract Builder setState(CheckState state);
 
+    public abstract Builder setMessage(String message);
+
     public abstract Builder setUrl(String url);
 
     public abstract Builder setStarted(Timestamp started);
diff --git a/java/com/google/gerrit/plugins/checks/CheckJson.java b/java/com/google/gerrit/plugins/checks/CheckJson.java
index 4b5e9f3..3ef8937 100644
--- a/java/com/google/gerrit/plugins/checks/CheckJson.java
+++ b/java/com/google/gerrit/plugins/checks/CheckJson.java
@@ -66,6 +66,7 @@
     info.patchSetId = check.key().patchSet().patchSetId;
     info.state = check.state();
 
+    info.message = check.message().orElse(null);
     info.url = check.url().orElse(null);
     info.started = check.started().orElse(null);
     info.finished = check.finished().orElse(null);
diff --git a/java/com/google/gerrit/plugins/checks/CheckUpdate.java b/java/com/google/gerrit/plugins/checks/CheckUpdate.java
index fd10148..315160d 100644
--- a/java/com/google/gerrit/plugins/checks/CheckUpdate.java
+++ b/java/com/google/gerrit/plugins/checks/CheckUpdate.java
@@ -23,6 +23,8 @@
 public abstract class CheckUpdate {
   public abstract Optional<CheckState> state();
 
+  public abstract Optional<String> message();
+
   public abstract Optional<String> url();
 
   public abstract Optional<Timestamp> started();
@@ -39,6 +41,8 @@
   public abstract static class Builder {
     public abstract Builder setState(CheckState state);
 
+    public abstract Builder setMessage(String message);
+
     public abstract Builder setUrl(String url);
 
     public abstract Builder setStarted(Timestamp started);
diff --git a/java/com/google/gerrit/plugins/checks/acceptance/testsuite/CheckOperationsImpl.java b/java/com/google/gerrit/plugins/checks/acceptance/testsuite/CheckOperationsImpl.java
index a348777..a6a1c02 100644
--- a/java/com/google/gerrit/plugins/checks/acceptance/testsuite/CheckOperationsImpl.java
+++ b/java/com/google/gerrit/plugins/checks/acceptance/testsuite/CheckOperationsImpl.java
@@ -125,6 +125,7 @@
 
   private static CheckUpdate toCheckUpdate(TestCheckUpdate testUpdate) {
     CheckUpdate.Builder update = CheckUpdate.builder();
+    testUpdate.message().ifPresent(update::setMessage);
     testUpdate.state().ifPresent(update::setState);
     testUpdate.started().ifPresent(update::setStarted);
     testUpdate.finished().ifPresent(update::setFinished);
diff --git a/java/com/google/gerrit/plugins/checks/acceptance/testsuite/TestCheckUpdate.java b/java/com/google/gerrit/plugins/checks/acceptance/testsuite/TestCheckUpdate.java
index e3230af..90864a6 100644
--- a/java/com/google/gerrit/plugins/checks/acceptance/testsuite/TestCheckUpdate.java
+++ b/java/com/google/gerrit/plugins/checks/acceptance/testsuite/TestCheckUpdate.java
@@ -27,6 +27,8 @@
 
   public abstract Optional<CheckState> state();
 
+  public abstract Optional<String> message();
+
   public abstract Optional<String> url();
 
   public abstract Optional<Timestamp> started();
@@ -47,6 +49,12 @@
 
     public abstract Builder state(CheckState state);
 
+    public abstract Builder message(String message);
+
+    public Builder clearMessage() {
+      return message("");
+    }
+
     public abstract Builder url(String url);
 
     public Builder clearUrl() {
diff --git a/java/com/google/gerrit/plugins/checks/api/CheckInfo.java b/java/com/google/gerrit/plugins/checks/api/CheckInfo.java
index 3096fec..77cbdef 100644
--- a/java/com/google/gerrit/plugins/checks/api/CheckInfo.java
+++ b/java/com/google/gerrit/plugins/checks/api/CheckInfo.java
@@ -33,6 +33,8 @@
 
   /** State that this check exited. */
   public CheckState state;
+  /** Short message explaining the check state. */
+  @Nullable public String message;
   /** Fully qualified URL to detailed result on the Checker's service. */
   @Nullable public String url;
   /** Timestamp of when this check was created. */
@@ -65,6 +67,7 @@
         && Objects.equals(other.patchSetId, patchSetId)
         && Objects.equals(other.checkerUuid, checkerUuid)
         && Objects.equals(other.state, state)
+        && Objects.equals(other.message, message)
         && Objects.equals(other.url, url)
         && Objects.equals(other.started, started)
         && Objects.equals(other.finished, finished)
@@ -83,6 +86,7 @@
         patchSetId,
         checkerUuid,
         state,
+        message,
         url,
         started,
         finished,
@@ -101,6 +105,7 @@
         .add("patchSetId", patchSetId)
         .add("checkerUuid", checkerUuid)
         .add("state", state)
+        .add("message", message)
         .add("url", url)
         .add("started", started)
         .add("finished", finished)
diff --git a/java/com/google/gerrit/plugins/checks/api/CheckInput.java b/java/com/google/gerrit/plugins/checks/api/CheckInput.java
index 633d2fb..2162ce3 100644
--- a/java/com/google/gerrit/plugins/checks/api/CheckInput.java
+++ b/java/com/google/gerrit/plugins/checks/api/CheckInput.java
@@ -25,6 +25,8 @@
   @Nullable public String checkerUuid;
   /** State of the check. */
   @Nullable public CheckState state;
+  /** Short message explaining the check state. */
+  @Nullable public String message;
   /** Fully qualified URL to detailed result on the Checker's service. */
   @Nullable public String url;
   /** Date/Time at which the checker started processing this check. */
@@ -40,6 +42,7 @@
     CheckInput other = (CheckInput) o;
     return Objects.equals(other.checkerUuid, checkerUuid)
         && Objects.equals(other.state, state)
+        && Objects.equals(other.message, message)
         && Objects.equals(other.url, url)
         && Objects.equals(other.started, started)
         && Objects.equals(other.finished, finished);
@@ -47,7 +50,7 @@
 
   @Override
   public int hashCode() {
-    return Objects.hash(checkerUuid, state, url, started, finished);
+    return Objects.hash(checkerUuid, state, message, url, started, finished);
   }
 
   @Override
@@ -55,6 +58,7 @@
     return MoreObjects.toStringHelper(this)
         .add("checkerUuid", checkerUuid)
         .add("state", state)
+        .add("message", message)
         .add("url", url)
         .add("started", started)
         .add("finished", finished)
diff --git a/java/com/google/gerrit/plugins/checks/api/PostCheck.java b/java/com/google/gerrit/plugins/checks/api/PostCheck.java
index ad011d7..d6934e7 100644
--- a/java/com/google/gerrit/plugins/checks/api/PostCheck.java
+++ b/java/com/google/gerrit/plugins/checks/api/PostCheck.java
@@ -117,6 +117,10 @@
       checkUpdateBuilder.setState(input.state);
     }
 
+    if (input.message != null) {
+      checkUpdateBuilder.setMessage(input.message.trim());
+    }
+
     if (input.url != null) {
       checkUpdateBuilder.setUrl(UrlValidator.clean(input.url));
     }
diff --git a/java/com/google/gerrit/plugins/checks/db/NoteDbCheck.java b/java/com/google/gerrit/plugins/checks/db/NoteDbCheck.java
index 2b52000..cb60d2c 100644
--- a/java/com/google/gerrit/plugins/checks/db/NoteDbCheck.java
+++ b/java/com/google/gerrit/plugins/checks/db/NoteDbCheck.java
@@ -17,6 +17,7 @@
   private NoteDbCheck() {}
 
   public CheckState state = CheckState.NOT_STARTED;
+  @Nullable public String message;
   @Nullable public String url;
   @Nullable public Timestamp started;
   @Nullable public Timestamp finished;
@@ -27,6 +28,9 @@
   Check toCheck(CheckKey key) {
     Check.Builder newCheck =
         Check.builder(key).setState(state).setCreated(created).setUpdated(updated);
+    if (message != null) {
+      newCheck.setMessage(message);
+    }
     if (url != null) {
       newCheck.setUrl(url);
     }
@@ -60,6 +64,11 @@
       state = update.state().get();
       modified = true;
     }
+    if (update.message().isPresent()
+        && !update.message().get().equals(Strings.nullToEmpty(message))) {
+      message = Strings.emptyToNull(update.message().get());
+      modified = true;
+    }
     if (update.url().isPresent() && !update.url().get().equals(Strings.nullToEmpty(url))) {
       url = Strings.emptyToNull(update.url().get());
       modified = true;
diff --git a/javatests/com/google/gerrit/plugins/checks/acceptance/api/CreateCheckIT.java b/javatests/com/google/gerrit/plugins/checks/acceptance/api/CreateCheckIT.java
index 1fc7c8a..85c176b 100644
--- a/javatests/com/google/gerrit/plugins/checks/acceptance/api/CreateCheckIT.java
+++ b/javatests/com/google/gerrit/plugins/checks/acceptance/api/CreateCheckIT.java
@@ -79,6 +79,7 @@
     CheckInfo info = checksApiFactory.revision(patchSetId).create(input).get();
     assertThat(info.checkerUuid).isEqualTo(checkerUuid.get());
     assertThat(info.state).isEqualTo(CheckState.RUNNING);
+    assertThat(info.message).isNull();
     assertThat(info.url).isNull();
     assertThat(info.started).isNull();
     assertThat(info.finished).isNull();
@@ -130,6 +131,19 @@
   }
 
   @Test
+  public void createCheckWithMessage() throws Exception {
+    CheckerUuid checkerUuid = checkerOperations.newChecker().repository(project).create();
+
+    CheckInput input = new CheckInput();
+    input.checkerUuid = checkerUuid.get();
+    input.message = "some message";
+
+    CheckInfo info = checksApiFactory.revision(patchSetId).create(input).get();
+    assertThat(info.message).isEqualTo(input.message);
+    assertThat(getCheck(project, patchSetId, checkerUuid).message()).hasValue(input.message);
+  }
+
+  @Test
   public void createCheckWithUrl() throws Exception {
     CheckerUuid checkerUuid = checkerOperations.newChecker().repository(project).create();
 
diff --git a/javatests/com/google/gerrit/plugins/checks/acceptance/api/UpdateCheckIT.java b/javatests/com/google/gerrit/plugins/checks/acceptance/api/UpdateCheckIT.java
index 3c37987..665b3eb 100644
--- a/javatests/com/google/gerrit/plugins/checks/acceptance/api/UpdateCheckIT.java
+++ b/javatests/com/google/gerrit/plugins/checks/acceptance/api/UpdateCheckIT.java
@@ -91,6 +91,26 @@
   }
 
   @Test
+  public void updateMessage() throws Exception {
+    CheckInput input = new CheckInput();
+    input.message = "some message";
+
+    CheckInfo info = checksApiFactory.revision(patchSetId).id(checkKey.checkerUuid()).update(input);
+    assertThat(info.message).isEqualTo(input.message);
+  }
+
+  @Test
+  public void unsetMessage() throws Exception {
+    checkOperations.check(checkKey).forUpdate().message("some message").upsert();
+
+    CheckInput input = new CheckInput();
+    input.message = "";
+
+    CheckInfo info = checksApiFactory.revision(patchSetId).id(checkKey.checkerUuid()).update(input);
+    assertThat(info.message).isNull();
+  }
+
+  @Test
   public void updateUrl() throws Exception {
     CheckInput input = new CheckInput();
     input.url = "http://example.com/my-check";
@@ -311,6 +331,7 @@
         .check(checkKey)
         .forUpdate()
         .state(CheckState.FAILED)
+        .message("some message")
         .url("https://www.example.com")
         .upsert();
 
@@ -318,6 +339,7 @@
     input.state = CheckState.NOT_STARTED;
     CheckInfo info = checksApiFactory.revision(patchSetId).id(checkKey.checkerUuid()).update(input);
 
+    assertThat(info.message).isEqualTo("some message");
     assertThat(info.url).isEqualTo("https://www.example.com");
   }
 }
diff --git a/javatests/com/google/gerrit/plugins/checks/acceptance/testsuite/CheckOperationsImplTest.java b/javatests/com/google/gerrit/plugins/checks/acceptance/testsuite/CheckOperationsImplTest.java
index 0b53666..b3166b6 100644
--- a/javatests/com/google/gerrit/plugins/checks/acceptance/testsuite/CheckOperationsImplTest.java
+++ b/javatests/com/google/gerrit/plugins/checks/acceptance/testsuite/CheckOperationsImplTest.java
@@ -72,6 +72,7 @@
     assertThat(foundCheck.patchSetId).isEqualTo(checkKey.patchSet().get());
     assertThat(foundCheck.checkerUuid).isEqualTo(checkerUuid.get());
     assertThat(foundCheck.state).isNotNull();
+    assertThat(foundCheck.message).isNull();
     assertThat(foundCheck.url).isNull();
     assertThat(foundCheck.started).isNull();
     assertThat(foundCheck.finished).isNull();
@@ -130,6 +131,26 @@
   }
 
   @Test
+  public void specifiedMessageIsRespectedForCheckCreation() throws Exception {
+    CheckerUuid checkerUuid = checkerOperations.newChecker().repository(project).create();
+    CheckKey checkKey = CheckKey.create(project, createChange().getPatchSetId(), checkerUuid);
+    checkOperations.newCheck(checkKey).message("some message").upsert();
+
+    CheckInfo check = getCheckFromServer(checkKey);
+    assertThat(check.message).isEqualTo("some message");
+  }
+
+  @Test
+  public void requestingNoMessageIsPossibleForCheckCreation() throws Exception {
+    CheckerUuid checkerUuid = checkerOperations.newChecker().create();
+    CheckKey checkKey = CheckKey.create(project, createChange().getPatchSetId(), checkerUuid);
+    checkOperations.newCheck(checkKey).clearMessage().upsert();
+
+    CheckInfo check = getCheckFromServer(checkKey);
+    assertThat(check.message).isNull();
+  }
+
+  @Test
   public void specifiedUrlIsRespectedForCheckCreation() throws Exception {
     CheckerUuid checkerUuid = checkerOperations.newChecker().repository(project).create();
     CheckKey checkKey = CheckKey.create(project, createChange().getPatchSetId(), checkerUuid);
@@ -259,6 +280,28 @@
   }
 
   @Test
+  public void messageOfExistingCheckCanBeRetrieved() throws Exception {
+    CheckerUuid checkerUuid = checkerOperations.newChecker().repository(project).create();
+    CheckKey checkKey = CheckKey.create(project, createChange().getPatchSetId(), checkerUuid);
+    checkOperations.newCheck(checkKey).message("some message").upsert();
+
+    Optional<String> message = checkOperations.check(checkKey).get().message();
+
+    assertThat(message).hasValue("some message");
+  }
+
+  @Test
+  public void emptyMessageOfExistingCheckCanBeRetrieved() throws Exception {
+    CheckerUuid checkerUuid = checkerOperations.newChecker().repository(project).create();
+    CheckKey checkKey = CheckKey.create(project, createChange().getPatchSetId(), checkerUuid);
+    checkOperations.newCheck(checkKey).clearMessage().upsert();
+
+    Optional<String> message = checkOperations.check(checkKey).get().message();
+
+    assertThat(message).isEmpty();
+  }
+
+  @Test
   public void urlOfExistingCheckCanBeRetrieved() throws Exception {
     CheckerUuid checkerUuid = checkerOperations.newChecker().repository(project).create();
     CheckKey checkKey = CheckKey.create(project, createChange().getPatchSetId(), checkerUuid);
@@ -369,6 +412,30 @@
   }
 
   @Test
+  public void messageCanBeUpdated() throws Exception {
+    CheckerUuid checkerUuid = checkerOperations.newChecker().repository(project).create();
+    CheckKey checkKey = CheckKey.create(project, createChange().getPatchSetId(), checkerUuid);
+    checkOperations.newCheck(checkKey).message("original message").upsert();
+
+    checkOperations.check(checkKey).forUpdate().message("updated message").upsert();
+
+    Optional<String> currentMessage = checkOperations.check(checkKey).get().message();
+    assertThat(currentMessage).hasValue("updated message");
+  }
+
+  @Test
+  public void messageCanBeCleared() throws Exception {
+    CheckerUuid checkerUuid = checkerOperations.newChecker().repository(project).create();
+    CheckKey checkKey = CheckKey.create(project, createChange().getPatchSetId(), checkerUuid);
+    checkOperations.newCheck(checkKey).message("original message").upsert();
+
+    checkOperations.check(checkKey).forUpdate().clearMessage().upsert();
+
+    Optional<String> currentMessage = checkOperations.check(checkKey).get().message();
+    assertThat(currentMessage).isEmpty();
+  }
+
+  @Test
   public void urlCanBeUpdated() throws Exception {
     CheckerUuid checkerUuid = checkerOperations.newChecker().repository(project).create();
     CheckKey checkKey = CheckKey.create(project, createChange().getPatchSetId(), checkerUuid);
@@ -452,6 +519,7 @@
     checkOperations
         .newCheck(checkKey)
         .state(CheckState.RUNNING)
+        .message("some message")
         .url("http://example.com/my-check")
         .started(new Timestamp(1234567L))
         .finished(new Timestamp(7654321L))
@@ -463,6 +531,7 @@
     assertThat(checkInfo.patchSetId).isEqualTo(check.key().patchSet().get());
     assertThat(checkInfo.checkerUuid).isEqualTo(check.key().checkerUuid().get());
     assertThat(checkInfo.state).isEqualTo(check.state());
+    assertThat(checkInfo.message).isEqualTo(check.message().get());
     assertThat(checkInfo.url).isEqualTo(check.url().get());
     assertThat(checkInfo.started).isEqualTo(check.started().get());
     assertThat(checkInfo.finished).isEqualTo(check.finished().get());
@@ -478,6 +547,7 @@
     CheckInput checkInput = new CheckInput();
     checkInput.checkerUuid = checkerUuid.get();
     checkInput.state = CheckState.SCHEDULED;
+    checkInput.message = "some message";
     checkInput.url = "http://example.com/my-check";
     checkInput.started = TimeUtil.nowTs();
     return checkInput;
diff --git a/src/main/resources/Documentation/rest-api-checks.md b/src/main/resources/Documentation/rest-api-checks.md
index c785e75..4e30e94 100644
--- a/src/main/resources/Documentation/rest-api-checks.md
+++ b/src/main/resources/Documentation/rest-api-checks.md
@@ -168,6 +168,7 @@
 | `patch_set_id`    |          | The patch set that this check applies to.
 | `checker_uuid`    |          | The [UUID](./rest-api-checkers.md#checker-id) of the checker that reported this check.
 | `state`           |          | The state as string-serialized form of [CheckState](#check-state)
+| `message`         | optional | Short message explaining the check state.
 | `url`             | optional | A fully-qualified URL pointing to the result of the check on the checker's infrastructure.
 | `started`         | optional | The [timestamp](../../../Documentation/rest-api.html#timestamp) of when the check started processing.
 | `finished`        | optional | The [timestamp](../../../Documentation/rest-api.html#timestamp) of when the check finished processing.
@@ -184,6 +185,7 @@
 | --------------- | -------- | ----------- |
 | `checker_uuid`  | optional | The name of the checker. Must be specified for checker creation. Optional only if updating a check and referencing the checker using the [UUID](./rest-api-checkers.md#checker-id) in the URL.
 | `state`         | optional | The state as string-serialized form of [CheckState](#check-state)
+| `message`       | optional | Short message explaining the check state.
 | `url`           | optional | A fully-qualified URL pointing to the result of the check on the checker's infrastructure.
 | `started`       | optional | The [timestamp](../../../Documentation/rest-api.html#timestamp) of when the check started processing.
 | `finished`      | optional | The [timestamp](../../../Documentation/rest-api.html#timestamp) of when the check finished processing.