How to reproduce: store an image on the file and try to use it this way string path = @"D:\img.png"; this.radLabel1.Text = "<html><img src=" + path + "><b>Test</b></html>"; Workaround: if possible embed the image in the assembly and use it as a resource this.radLabel1.Text = "<html><img src=res:_1133506_RadLabelLinkHtmlLike.img.png><b>Test</b></html>";