This paper presents a multi-fractal antenna operating in ultra wide band range for WLAN and WiMAX applications. The novel idea of multi-fractal geometry is introduced into the conventional triangular patch antenna with microstrip feed. The addition of Koch and Sierpinski fractal techniques gives rise to better impedance bandwidth and return loss characteristics. The proposed antenna exhibits resonant frequency at 5.48 GHz with a return loss of -31.9dB to satisfy the band specifications for wireless LAN applications IEEE802.11a (5.15-5.35 GHz, 5.725-5.875 GHz) and WiMAX application at 5GHz (5.25-5.85 GHz). It is found that the antenna exhibits omni-directional radiation pattern in H plane with a maximum gain of 3.5dB. The antenna exhibits a stable radiation pattern throughout the operating frequency range of 4.68-6.43 GHz. The antenna covers the upper and lower bands of WLAN operating frequencies. The simulation was performed in High Frequency Structure Simulator. © 2013 IEEE.