RadToolTip is pretty simple control whose ControlTemplate consists of a single ContentPresernter only. This means that everything you set as a ContentTempalte via RadToolTipService.ToolTipContentTemplate property will create the whole visual part of control (the part you see). Please also have in mind if you set RadToolTipContentView as first -level control in the ToolTipContentTemplate you can benefit from the telerik predefined themes. Please check out the sample in which different templates are applied on 3 Ellipses.