A preliminary study has been carried out on the electrical properties and chemical purity of epitaxial layers of cadmium mercury telluride (CMT) grown by metal‐organic vapor phase epitaxy (MOVPE). It has been shown that the mobility of such layers grown at 410 °C are comparable with bulk CMT of equivalent carrier concentration. SIMS profile studies of trace impurities in the epitaxial layers and CdTe substrates used for epitaxial deposition revealed significant impurity concentration enhancement (ICE effect) for a number of elements (Li, Na, K, Al, Ga, In and Mn) at the CdTe/CMT interface: some of these elements (Li, Na, K, Al and In) also showed this ice effect at the subsequent CMT/CdTe interface. The magnitude of the ICE effect could be quite large (a factor of ∼ 100 for Li) but its origin was not identified although potential mechanisms for its formation are discussed.