diff --git a/dom/base/nsGlobalWindow.cpp b/dom/base/nsGlobalWindow.cpp
index 33b959db714..b91d304c264 100644
--- a/dom/base/nsGlobalWindow.cpp
+++ b/dom/base/nsGlobalWindow.cpp
@@ -283,6 +283,9 @@ static bool                 gDragServiceDisabled       = false;
 static FILE                *gDumpFile                  = nsnull;
 static PRUint64             gNextWindowID              = 0;
 static PRUint32             gSerialCounter             = 0;
+static PRUint32             gTimeoutsRecentlySet       = 0;
+static TimeStamp            gLastRecordedRecentTimeouts;
+#define STATISTICS_INTERVAL (30 * PR_MSEC_PER_SEC)
 
 #ifdef DEBUG_jst
 PRInt32 gTimeoutCnt                                    = 0;
@@ -9054,6 +9057,7 @@ nsGlobalWindow::SetTimeoutOrInterval(nsIScriptTimeoutHandler *aHandler,
     timeout->mPrincipal = ourPrincipal;
   }
 
+  ++gTimeoutsRecentlySet;
   TimeDuration delta = TimeDuration::FromMilliseconds(realInterval);
 
   if (!IsFrozen() && !mTimeoutsSuspendDepth) {
@@ -9228,6 +9232,16 @@ nsGlobalWindow::RunTimeout(nsTimeout *aTimeout)
     return;
   }
 
+  // Record telemetry information about timers set recently.
+  TimeDuration recordingInterval = TimeDuration::FromMilliseconds(STATISTICS_INTERVAL);
+  if (gLastRecordedRecentTimeouts.IsNull() ||
+      now - gLastRecordedRecentTimeouts > recordingInterval) {
+    PRUint32 count = gTimeoutsRecentlySet;
+    gTimeoutsRecentlySet = 0;
+    Telemetry::Accumulate(Telemetry::DOM_TIMERS_RECENTLY_SET, count);
+    gLastRecordedRecentTimeouts = now;
+  }
+
   // Insert a dummy timeout into the list of timeouts between the
   // portion of the list that we are about to process now and those
   // timeouts that will be processed in a future call to
diff --git a/toolkit/components/telemetry/TelemetryHistograms.h b/toolkit/components/telemetry/TelemetryHistograms.h
index 3e7f7701c48..be77bc7b6d9 100644
--- a/toolkit/components/telemetry/TelemetryHistograms.h
+++ b/toolkit/components/telemetry/TelemetryHistograms.h
@@ -324,6 +324,7 @@ HISTOGRAM_BOOLEAN(XMLHTTPREQUEST_ASYNC_OR_SYNC, "Type of XMLHttpRequest, async o
  * DOM telemetry.
  */
 HISTOGRAM(DOM_TIMERS_FIRED_PER_NATIVE_TIMEOUT, 1, 3000, 10, EXPONENTIAL, "DOM: Timer handlers called per native timer expiration")
+HISTOGRAM(DOM_TIMERS_RECENTLY_SET, 1, 3000, 10, EXPONENTIAL, "DOM: setTimeout/setInterval calls recently (last 30s or more)")
 
 /**
  * DOM Storage telemetry.