To reproduce: public Form1() { InitializeComponent(); this.radRichTextEditor1.IsReadOnly = true; } Workaround: private void Form1_Load(object sender, EventArgs e) { this.radRichTextEditor1.IsReadOnly = true; Telerik.WinControls.RichTextEditor.UI.DocumentWebLayoutPresenter webLayoutPresenter = this.radRichTextEditor1.RichTextBoxElement.ActiveEditorPresenter as Telerik.WinControls.RichTextEditor.UI.DocumentWebLayoutPresenter; webLayoutPresenter.Caret.Width = 0; }