A miniaturized Multi-input Multi-output (MIMO) antenna is proposed for Ultra-wideband (UWB) applications having capability to mitigate interference with the WLAN (5.15GHZ-5.85GHZ) operating band. A ‘spider’ shape structure is etched on the ground as a decoupling structure to obtain impedance matching as well as desired isolation. W-LAN notched band in the entire Ultra Wide band is obtained by etching a couple of straight line on the ground plane. A very compact UWB-MIMO antenna with overall dimension of 20×20 mm2 has been proposed which is smaller than most of other MIMO antennas designed for UWB. Impedance bandwidth for the proposed MIMO antenna is 2.9-11.1GHz with -10dB refection coefficient and isolation better than -16.5dB in the total Ultra Wide band is achieved.