diff --git a/src/app/components/table/table.ts b/src/app/components/table/table.ts
index 3071cda3779..04c2e982142 100644
--- a/src/app/components/table/table.ts
+++ b/src/app/components/table/table.ts
@@ -2426,11 +2426,13 @@ export class Table implements OnInit, AfterViewInit, AfterContentInit, Blockable
     }
 
     toggleRow(rowData: any, event?: Event) {
-        if (!this.dataKey) {
-            throw new Error('dataKey must be defined to use row expansion');
+        if (!this.dataKey && !this.groupRowsBy) {
+            throw new Error('dataKey or groupRowsBy must be defined to use row expansion');
         }
 
-        let dataKeyValue = String(ObjectUtils.resolveFieldData(rowData, this.dataKey));
+        let dataKeyValue = this.groupRowsBy ?
+            String(ObjectUtils.resolveFieldData(rowData, this.groupRowsBy)) :
+            String(ObjectUtils.resolveFieldData(rowData, this.dataKey));
 
         if (this.expandedRowKeys[dataKeyValue] != null) {
             delete this.expandedRowKeys[dataKeyValue];
@@ -2460,7 +2462,9 @@ export class Table implements OnInit, AfterViewInit, AfterContentInit, Blockable
     }
 
     isRowExpanded(rowData: any): boolean {
-        return this.expandedRowKeys[String(ObjectUtils.resolveFieldData(rowData, this.dataKey))] === true;
+        return this.groupRowsBy ?
+            this.expandedRowKeys[String(ObjectUtils.resolveFieldData(rowData, this.groupRowsBy))] === true :
+            this.expandedRowKeys[String(ObjectUtils.resolveFieldData(rowData, this.dataKey))] === true;
     }
 
     isRowEditing(rowData: any): boolean {