diff --git a/controller/metrics/prommetrics.go b/controller/metrics/prommetrics.go
index 02ed83af92..3e55ba1ccb 100644
--- a/controller/metrics/prommetrics.go
+++ b/controller/metrics/prommetrics.go
@@ -58,6 +58,13 @@ var (
 		nil,
 	)
 
+	MetricRolloutInfoReplicasUpdated = prometheus.NewDesc(
+		"rollout_info_replicas_updated",
+		"The number of updated replicas per rollout.",
+		namespaceNameLabels,
+		nil,
+	)
+
 	MetricRolloutEventsTotal = prometheus.NewCounterVec(
 		prometheus.CounterOpts{
 			Name: "rollout_events_total",
diff --git a/controller/metrics/rollout_test.go b/controller/metrics/rollout_test.go
index b10af8b184..2afa173b3e 100644
--- a/controller/metrics/rollout_test.go
+++ b/controller/metrics/rollout_test.go
@@ -113,7 +113,13 @@ rollout_info_replicas_available{name="guestbook-bluegreen",namespace="default"}
 rollout_info_replicas_desired{name="guestbook-bluegreen",namespace="default"} 1
 # HELP rollout_info_replicas_unavailable The number of unavailable replicas per rollout.
 # TYPE rollout_info_replicas_unavailable gauge
-rollout_info_replicas_unavailable{name="guestbook-bluegreen",namespace="default"} 0`,
+rollout_info_replicas_unavailable{name="guestbook-bluegreen",namespace="default"} 0
+# HELP rollout_info_replicas_unavailable The number of unavailable replicas per rollout.
+# TYPE rollout_info_replicas_unavailable gauge
+rollout_info_replicas_unavailable{name="guestbook-bluegreen",namespace="default"} 0
+# HELP rollout_info_replicas_updated The number of updated replicas per rollout.
+# TYPE rollout_info_replicas_updated gauge
+rollout_info_replicas_updated{name="guestbook-bluegreen",namespace="default"} 0`,
 		},
 
 		{
@@ -131,7 +137,13 @@ rollout_info_replicas_available{name="guestbook-bluegreen",namespace="default"}
 rollout_info_replicas_desired{name="guestbook-bluegreen",namespace="default"} 1
 # HELP rollout_info_replicas_unavailable The number of unavailable replicas per rollout.
 # TYPE rollout_info_replicas_unavailable gauge
-rollout_info_replicas_unavailable{name="guestbook-bluegreen",namespace="default"} 0`,
+rollout_info_replicas_unavailable{name="guestbook-bluegreen",namespace="default"} 0
+# HELP rollout_info_replicas_unavailable The number of unavailable replicas per rollout.
+# TYPE rollout_info_replicas_unavailable gauge
+rollout_info_replicas_unavailable{name="guestbook-bluegreen",namespace="default"} 0
+# HELP rollout_info_replicas_updated The number of updated replicas per rollout.
+# TYPE rollout_info_replicas_updated gauge
+rollout_info_replicas_updated{name="guestbook-bluegreen",namespace="default"} 0`,
 		},
 		{
 			fakeCanaryRollout,
@@ -148,7 +160,13 @@ rollout_info_replicas_available{name="guestbook-canary",namespace="default"} 1
 rollout_info_replicas_desired{name="guestbook-canary",namespace="default"} 1
 # HELP rollout_info_replicas_unavailable The number of unavailable replicas per rollout.
 # TYPE rollout_info_replicas_unavailable gauge
-rollout_info_replicas_unavailable{name="guestbook-canary",namespace="default"} 0`,
+rollout_info_replicas_unavailable{name="guestbook-canary",namespace="default"} 0
+# HELP rollout_info_replicas_unavailable The number of unavailable replicas per rollout.
+# TYPE rollout_info_replicas_unavailable gauge
+rollout_info_replicas_unavailable{name="guestbook-canary",namespace="default"} 0
+# HELP rollout_info_replicas_updated The number of updated replicas per rollout.
+# TYPE rollout_info_replicas_updated gauge
+rollout_info_replicas_updated{name="guestbook-canary",namespace="default"} 0`,
 		},
 	}
 
diff --git a/controller/metrics/rollouts.go b/controller/metrics/rollouts.go
index 54a0c8af01..3d25de5a72 100644
--- a/controller/metrics/rollouts.go
+++ b/controller/metrics/rollouts.go
@@ -131,6 +131,7 @@ func collectRollouts(ch chan<- prometheus.Metric, rollout *v1alpha1.Rollout) {
 	addGauge(MetricRolloutInfoReplicasAvailable, float64(rollout.Status.AvailableReplicas))
 	addGauge(MetricRolloutInfoReplicasUnavailable, float64(rollout.Status.Replicas-rollout.Status.AvailableReplicas))
 	addGauge(MetricRolloutInfoReplicasDesired, float64(defaults.GetReplicasOrDefault(rollout.Spec.Replicas)))
+	addGauge(MetricRolloutInfoReplicasUpdated, float64(rollout.Status.UpdatedReplicas))
 
 	// DEPRECATED
 	addGauge(MetricRolloutPhase, boolFloat64(calculatedPhase == RolloutCompleted), strategyType, string(RolloutCompleted))
diff --git a/docs/features/controller-metrics.md b/docs/features/controller-metrics.md
index 72e2df3561..def8bba734 100644
--- a/docs/features/controller-metrics.md
+++ b/docs/features/controller-metrics.md
@@ -46,10 +46,12 @@ You can import this Dashboard in your Grafana installation [as a JSON file](http
 The Argo Rollouts controller publishes the following prometheus metrics about Argo Rollout objects.
 
 | Name                                | Description |
-| ----------------------------------- | ----------- |
+|-------------------------------------| ----------- |
 | `rollout_info`                      | Information about rollout. |
 | `rollout_info_replicas_available`   | The number of available replicas per rollout. |
 | `rollout_info_replicas_unavailable` | The number of unavailable replicas per rollout. |
+| `rollout_info_replicas_desired`     | The number of desired replicas per rollout. |
+| `rollout_info_replicas_updated`     | The number of updated replicas per rollout. |
 | `rollout_phase`                     | Information on the state of the rollout. |
 | `rollout_reconcile`                 | Rollout reconciliation performance. |
 | `rollout_reconcile_error`           | Error occurring during the rollout. |