To reproduce: please refer to the attached sample project and gif file illustrating the behavior. Workaround: in order to cancel adding of the new row, you can call the MasterView.TableAddNewRow.CancelAddNewRow method: private void radGridView1_UserAddingRow(object sender, Telerik.WinControls.UI.GridViewRowCancelEventArgs e) { e.Cancel = true; this.radGridView1.MasterView.TableAddNewRow.CancelAddNewRow(); int index = this.radGridView1.Rows.Count; this.radGridView1.Rows.Add(index, "Row" + index); }