This paper introduces a design of planar array of multiband microstrip antennas for purposes of medical microwave imaging. The target application is breast microwave tomography. The proposed array achieves low level mutual coupling between its elements which is an important parameter for signal integrity during imaging process. Measurements done in the near field regions as in the case of medical imaging are affected greatly by the elements mutual coupling. The proposed array satisfies that requirement. The achieved low coupling level is reached through suitable orientation of each individual element and a wise choice of elements separation and array geometry.