The reverse leakage current in strained multiple quantum well (MQW) p-i-n structures has been measured for a range of different dimensions and strain. The magnitude of the leakage current is found to be dependent on the average strain of the MQW, the total MQW thickness and the thickness of the capping layer. Plan view transmission electron microscopy shows that misfit dislocation arrays form primarily at the upper and lower MQW interfaces and the total density of these determine the leakage current. (C) 1995 American Institute of Physics.