Binary blends of acrylonitrile-co-butadiene rubber and ethylene propylene diene monomer rubber are immiscible. However, they can be made compatible by addition of a third elastomer viz., chlorinated polyethylene or chlorosulphonated polyethylene in small concentrations. Various sophisticated analytical techniques, e.g., ultrasonic velocity measurements in solutions, infrared spectroscopy of solution cast films, thermo-mechanical analysis, processing characteristics through rubber process analyzer (RPA-2000), determination of the vulcanizate properties, and also phase morphology studies by atomic force microscopy have been made to elucidate compatibility and its effect on end-use properties of the evolved blends.