diff --git a/server/etcdserver/metrics.go b/server/etcdserver/metrics.go
index 7af0e7354d0..ea1fce461b7 100644
--- a/server/etcdserver/metrics.go
+++ b/server/etcdserver/metrics.go
@@ -118,6 +118,12 @@ var (
 		Name:      "lease_expired_total",
 		Help:      "The total number of expired leases.",
 	})
+	rangeResponseKvCount = prometheus.NewHistogramVec(prometheus.HistogramOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "range_response_kv_count",
+		Help:      "The number of KVs returned by range calls.",
+	}, []string{"range_begin"})
 
 	currentVersion = prometheus.NewGaugeVec(prometheus.GaugeOpts{
 		Namespace: "etcd",
@@ -168,6 +174,7 @@ func init() {
 	prometheus.MustRegister(slowReadIndex)
 	prometheus.MustRegister(readIndexFailed)
 	prometheus.MustRegister(leaseExpired)
+	prometheus.MustRegister(rangeResponseKvCount)
 	prometheus.MustRegister(currentVersion)
 	prometheus.MustRegister(currentGoVersion)
 	prometheus.MustRegister(serverID)
diff --git a/server/etcdserver/v3_server.go b/server/etcdserver/v3_server.go
index 07d1f546c9f..d32c52a6a1c 100644
--- a/server/etcdserver/v3_server.go
+++ b/server/etcdserver/v3_server.go
@@ -116,6 +116,11 @@ func (s *EtcdServer) Range(ctx context.Context, r *pb.RangeRequest) (*pb.RangeRe
 				traceutil.Field{Key: "response_count", Value: len(resp.Kvs)},
 				traceutil.Field{Key: "response_revision", Value: resp.Header.Revision},
 			)
+
+			// collect the metric on very large responses only, because the key dimensionality might blow up Prometheus.
+			if rangeResponseKvCount != nil && len(resp.Kvs) > 1000 {
+				rangeResponseKvCount.WithLabelValues(string(r.Key)).Observe(float64(len(resp.Kvs)))
+			}
 		}
 		trace.LogIfLong(traceThreshold)
 	}(time.Now())