Two-port MIMO antenna is proposed for ultrawide band wireless applications with triple notch bands. The proposed antenna is offering the operating frequency band ranging from 3.1 GHz to 10.6 GHz. Three notch bands at 4.56, 7.25, and 9.08 GHz are introduced to eliminate the interference with exiting bands. Moreover, a prototype of the proposed structure is fabricated, and simulated results are validated with measured experimental results. The proposed antenna shows the almost stable radiation characteristics throughout the operating band with an almost stable gain of about 5 dBi. Mutual coupling between both ports is suppressed to the value of −25 dB within the operating frequency band. Diversity characteristics for a MIMO performance are analysed in terms of envelope correlation coefficient, total active reflection coefficient, diversity gain, multiplexing efficiency, and mean effective gain. The proposed antenna is easily integrable with the other MMIC devices as it carries a simple structure.