diff --git a/pkg/apis/elasticsearch/v1/name.go b/pkg/apis/elasticsearch/v1/name.go
index bfb37c8ec3..4d2dd1c036 100644
--- a/pkg/apis/elasticsearch/v1/name.go
+++ b/pkg/apis/elasticsearch/v1/name.go
@@ -54,8 +54,14 @@ func validateNames(es *Elasticsearch) error {
 	if len(es.Name) > common_name.MaxResourceNameLength {
 		return errors.Errorf("name exceeds maximum allowed length of %d", common_name.MaxResourceNameLength)
 	}
+	nodeSetNames := map[string]struct{}{}
 	// validate ssets
 	for _, nodeSet := range es.Spec.NodeSets {
+		if _, ok := nodeSetNames[nodeSet.Name]; ok {
+			return errors.Errorf("duplicated nodeSet name: '%s'", nodeSet.Name)
+		}
+		nodeSetNames[nodeSet.Name] = struct{}{}
+
 		if errs := apimachineryvalidation.NameIsDNSSubdomain(nodeSet.Name, false); len(errs) > 0 {
 			return errors.Errorf("invalid nodeSet name '%s': [%s]", nodeSet.Name, strings.Join(errs, ","))
 		}
diff --git a/pkg/apis/elasticsearch/v1/name_test.go b/pkg/apis/elasticsearch/v1/name_test.go
index 83bbe150bb..22688b0c62 100644
--- a/pkg/apis/elasticsearch/v1/name_test.go
+++ b/pkg/apis/elasticsearch/v1/name_test.go
@@ -46,6 +46,13 @@ func TestValidate(t *testing.T) {
 			wantErr:       true,
 			wantErrMsg:    "invalid nodeSet name",
 		},
+		{
+			name:          "duplicated nodeSet names",
+			esName:        "test-es",
+			nodeSpecNames: []string{"default", "default"},
+			wantErr:       true,
+			wantErrMsg:    "duplicated nodeSet name",
+		},
 	}
 
 	for _, tc := range testCases {
diff --git a/pkg/apis/elasticsearch/v1beta1/name.go b/pkg/apis/elasticsearch/v1beta1/name.go
index 2fd8bb0bf7..be79615025 100644
--- a/pkg/apis/elasticsearch/v1beta1/name.go
+++ b/pkg/apis/elasticsearch/v1beta1/name.go
@@ -54,8 +54,14 @@ func validateNames(es *Elasticsearch) error {
 	if len(es.Name) > common_name.MaxResourceNameLength {
 		return errors.Errorf("name exceeds maximum allowed length of %d", common_name.MaxResourceNameLength)
 	}
+	nodeSetNames := map[string]struct{}{}
 	// validate ssets
 	for _, nodeSet := range es.Spec.NodeSets {
+		if _, ok := nodeSetNames[nodeSet.Name]; ok {
+			return errors.Errorf("duplicated nodeSet name: '%s'", nodeSet.Name)
+		}
+
+		nodeSetNames[nodeSet.Name] = struct{}{}
 		if errs := apimachineryvalidation.NameIsDNSSubdomain(nodeSet.Name, false); len(errs) > 0 {
 			return errors.Errorf("invalid nodeSet name '%s': [%s]", nodeSet.Name, strings.Join(errs, ","))
 		}
diff --git a/pkg/apis/elasticsearch/v1beta1/name_test.go b/pkg/apis/elasticsearch/v1beta1/name_test.go
index 09f8b77a7f..876108ff06 100644
--- a/pkg/apis/elasticsearch/v1beta1/name_test.go
+++ b/pkg/apis/elasticsearch/v1beta1/name_test.go
@@ -46,6 +46,13 @@ func TestValidate(t *testing.T) {
 			wantErr:       true,
 			wantErrMsg:    "invalid nodeSet name",
 		},
+		{
+			name:          "duplicated nodeSet names",
+			esName:        "test-es",
+			nodeSpecNames: []string{"default", "default"},
+			wantErr:       true,
+			wantErrMsg:    "duplicated nodeSet name",
+		},
 	}
 
 	for _, tc := range testCases {