diff --git a/pkg/operator/ceph/webhook.go b/pkg/operator/ceph/webhook.go
index dc1b90ebd..1680961a3 100644
--- a/pkg/operator/ceph/webhook.go
+++ b/pkg/operator/ceph/webhook.go
@@ -17,6 +17,8 @@ limitations under the License.
 package operator
 
 import (
+	"os"
+
 	"github.com/pkg/errors"
 	"github.com/rook/rook/pkg/clusterd"
 	"github.com/rook/rook/pkg/operator/ceph/csi"
@@ -26,7 +28,6 @@ import (
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/intstr"
-	"os"
 )
 
 const (
@@ -122,7 +123,7 @@ func createWebhookDeployment(context *clusterd.Context, admissionImage string) e
 	secretVolumeMount := getSecretVolumeMount()
 
 	antiAffinity := csi.GetPodAntiAffinity(k8sutil.AppAttr, appName)
-	admissionControllerDeployment := getDeployment(secretVolume, antiAffinity, admissionImage, admission_parameters, secretVolumeMount)
+	admissionControllerDeployment := getDeployment(context, secretVolume, antiAffinity, admissionImage, admission_parameters, secretVolumeMount)
 
 	err := k8sutil.CreateDeployment(context.Clientset, appName, namespace, &admissionControllerDeployment)
 	if err != nil {
@@ -132,8 +133,17 @@ func createWebhookDeployment(context *clusterd.Context, admissionImage string) e
 	return nil
 }
 
-func getDeployment(secretVolume corev1.Volume, antiAffinity corev1.PodAntiAffinity, admissionImage string, admission_parameters []string, secretVolumeMount corev1.VolumeMount) v1.Deployment {
+func getDeployment(context *clusterd.Context, secretVolume corev1.Volume, antiAffinity corev1.PodAntiAffinity,
+	admissionImage string, admission_parameters []string, secretVolumeMount corev1.VolumeMount) v1.Deployment {
 	var replicas int32 = 2
+	nodes, err := context.Clientset.CoreV1().Nodes().List(metav1.ListOptions{})
+	if err == nil {
+		if len(nodes.Items) == 1 {
+			replicas = 1
+		}
+	} else {
+		logger.Errorf("failed to get nodes. Defaulting the number of replicas of admission controller pods to 2. %v", err)
+	}
 
 	admissionControllerDeployment := v1.Deployment{
 		ObjectMeta: metav1.ObjectMeta{