Use the following code: this.radLabel1.Font = new Font("Segoe UI", 11); this.radLabel1.Text = "<html> Sample <strong> strong </strong> text to render. <br/> Please <u><strong>underline this here</strong></u> and make it strong."; The underlined text is not aligned correctly. If you change the font size to 14, then the empty spaces between the words in the underlined text are replaced with "_" and they are visible. Workaround: set the TextWrap property to false