This paper presents a MIMO array design with a reduced number of antennas of a 2×5 combination with 2 transmitting antennas and 5 receiving antennas. The system is designed to have a compact size for UWB microwave imaging in medical application. A suitable compact UWB antenna is designed with a fractional bandwidth of more than 128%, which achieves a good UWB performances. The mutual coupling within the array is investigated and the numerical results show the accuracy of the designed system for the medical applications.