A novel triple frequency patch antenna for WLAN/WiMAX applications is proposed and investigated in this paper. The antenna proposed is composed of three radiating elements: Stub1, Stub2 and Stub3. By adjusting the lengths of the three Stubs, three resonant frequencies can be achieved and adjusted separately. We present a microstrip patch antenna for worldwide interoperability for microwave access (WiMAX) standard at 3.5/5.5 GHz bands and wireless local area network (WLAN) operates at 2.4/5.2 GHz bands. This design results in a reduction in size and weight and allows integration in hand-held devices. Furthermore, nearly omnidirectional radiation patterns, reflection coefficient and gain over the operating bands have been obtained.