A compact triple-band two-element multiple-input-multiple-output (MIMO) antenna is presented for WiMAX/WLAN applications. The MIMO antenna is designed on Rogers RT/duroid 5880 substrate and composed by one T-shaped stub and two asymmetrical inverted L-shaped stubs loaded rectangular monopoles placed orthogonally at a distance of 10 mm to achieve triple operating bands, high isolation and optimum diversity between antenna elements. The proposed compact triple-band MIMO antenna is resonating at 2.6/3.52/5.42 GHz frequencies and provides isolation more than −15 dB over operating bands. The diversity performance is evaluated through envelope correlation coefficient (ECC) with less than 0.015 and diversity gain (DG) more than 9.92 over operating bands.