diff --git a/hadoop-mapreduce-project/CHANGES.txt b/hadoop-mapreduce-project/CHANGES.txt
index 3b1fd05da51..c848dc51499 100644
--- a/hadoop-mapreduce-project/CHANGES.txt
+++ b/hadoop-mapreduce-project/CHANGES.txt
@@ -19,6 +19,9 @@ Release 2.4.0 - UNRELEASED
   OPTIMIZATIONS
 
   BUG FIXES
+    
+    MAPREDUCE-5746. Job diagnostics can implicate wrong task for a failed job.
+    (Jason Lowe via kasha)
 
 Release 2.3.1 - UNRELEASED
 
diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/jobhistory/JobHistoryParser.java b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/jobhistory/JobHistoryParser.java
index 9d6f579c44d..19e2a51a132 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/jobhistory/JobHistoryParser.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/jobhistory/JobHistoryParser.java
@@ -353,8 +353,10 @@ public class JobHistoryParser implements HistoryEventHandler {
     taskInfo.error = StringInterner.weakIntern(event.getError());
     taskInfo.failedDueToAttemptId = event.getFailedAttemptID();
     taskInfo.counters = event.getCounters();
-    info.errorInfo = "Task " + taskInfo.taskId +" failed " +
-    taskInfo.attemptsMap.size() + " times ";
+    if (info.errorInfo.isEmpty()) {
+      info.errorInfo = "Task " + taskInfo.taskId + " failed " +
+          taskInfo.attemptsMap.size() + " times ";
+    }
   }
 
   private void handleTaskStartedEvent(TaskStartedEvent event) {
diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-hs/src/test/java/org/apache/hadoop/mapreduce/v2/hs/TestJobHistoryParsing.java b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-hs/src/test/java/org/apache/hadoop/mapreduce/v2/hs/TestJobHistoryParsing.java
index 4551b61e198..7893dbf5f04 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-hs/src/test/java/org/apache/hadoop/mapreduce/v2/hs/TestJobHistoryParsing.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-hs/src/test/java/org/apache/hadoop/mapreduce/v2/hs/TestJobHistoryParsing.java
@@ -41,6 +41,8 @@ import org.apache.hadoop.fs.CommonConfigurationKeysPublic;
 import org.apache.hadoop.fs.FSDataInputStream;
 import org.apache.hadoop.fs.FileContext;
 import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.mapreduce.Counters;
+import org.apache.hadoop.mapreduce.JobID;
 import org.apache.hadoop.mapreduce.MRJobConfig;
 import org.apache.hadoop.mapreduce.TaskID;
 import org.apache.hadoop.mapreduce.TypeConverter;
@@ -52,7 +54,9 @@ import org.apache.hadoop.mapreduce.jobhistory.JobHistoryParser.AMInfo;
 import org.apache.hadoop.mapreduce.jobhistory.JobHistoryParser.JobInfo;
 import org.apache.hadoop.mapreduce.jobhistory.JobHistoryParser.TaskAttemptInfo;
 import org.apache.hadoop.mapreduce.jobhistory.JobHistoryParser.TaskInfo;
+import org.apache.hadoop.mapreduce.jobhistory.TaskFailedEvent;
 import org.apache.hadoop.mapreduce.jobhistory.TaskFinishedEvent;
+import org.apache.hadoop.mapreduce.jobhistory.TaskStartedEvent;
 import org.apache.hadoop.mapreduce.v2.api.records.JobId;
 import org.apache.hadoop.mapreduce.v2.api.records.JobState;
 import org.apache.hadoop.mapreduce.v2.api.records.TaskAttemptId;
@@ -70,7 +74,6 @@ import org.apache.hadoop.mapreduce.v2.app.job.event.TaskAttemptEventType;
 import org.apache.hadoop.mapreduce.v2.hs.HistoryFileManager.HistoryFileInfo;
 import org.apache.hadoop.mapreduce.v2.hs.TestJobHistoryEvents.MRAppWithHistory;
 import org.apache.hadoop.mapreduce.v2.hs.webapp.dao.JobsInfo;
-import org.apache.hadoop.mapreduce.v2.jobhistory.FileNameIndexUtils;
 import org.apache.hadoop.mapreduce.v2.jobhistory.JobHistoryUtils;
 import org.apache.hadoop.mapreduce.v2.jobhistory.JobIndexInfo;
 import org.apache.hadoop.net.DNSToSwitchMapping;
@@ -726,4 +729,40 @@ public class TestJobHistoryParsing {
     assertNull(test.getAMInfos());
 
   }
+
+  @Test
+  public void testMultipleFailedTasks() throws Exception {
+    JobHistoryParser parser =
+        new JobHistoryParser(Mockito.mock(FSDataInputStream.class));
+    EventReader reader = Mockito.mock(EventReader.class);
+    final AtomicInteger numEventsRead = new AtomicInteger(0); // Hack!
+    final org.apache.hadoop.mapreduce.TaskType taskType =
+        org.apache.hadoop.mapreduce.TaskType.MAP;
+    final TaskID[] tids = new TaskID[2];
+    JobID jid = new JobID("1", 1);
+    tids[0] = new TaskID(jid, taskType, 0);
+    tids[1] = new TaskID(jid, taskType, 1);
+    Mockito.when(reader.getNextEvent()).thenAnswer(
+        new Answer<HistoryEvent>() {
+          public HistoryEvent answer(InvocationOnMock invocation)
+              throws IOException {
+            // send two task start and two task fail events for tasks 0 and 1
+            int eventId = numEventsRead.getAndIncrement();
+            TaskID tid = tids[eventId & 0x1];
+            if (eventId < 2) {
+              return new TaskStartedEvent(tid, 0, taskType, "");
+            }
+            if (eventId < 4) {
+              TaskFailedEvent tfe = new TaskFailedEvent(tid, 0, taskType,
+                  "failed", "FAILED", null, new Counters());
+              tfe.setDatum(tfe.getDatum());
+              return tfe;
+            }
+            return null;
+          }
+        });
+    JobInfo info = parser.parse(reader);
+    assertTrue("Task 0 not implicated",
+        info.getErrorInfo().contains(tids[0].toString()));
+  }
 }