A tri-band slot loaded microstrip antenna is proposed. The tri-band characteristics of antenna are achieved by incorporating a combination of symmetrical Y-shaped and asymmetrical U-shaped slot. The Y-shaped slot is placed symmetrically where as U-shaped slot is placed asymmetrically to the center of the patch to achieve the desired tri-band characteristics. The return loss characteristics show that the percentage impedance bandwidth achieved for Global Positioning System (GPS), Wireless Fidelity (Wi-Fi), and Wireless Metropolitan Area networks (WiMAX) band are 1.78%, 5.28%, and 10.41%, respectively. The parametric study of the antenna is presented.