The effect of benazepril (CGS 14824), 20 mg/day orally, on the steady-state pharmaco-dynamics and plasma levels of the anticoagulants, warfarin and acenocoumarol, was studied in healthy volunteers. The anticoagulant activity of acenocoumarol was not affected by benazepril; there was an apparent slight but statistically significant reduction of the anticoagulant effect of warfarin. The magnitude of the inhibitory effect was considered not to be clinically important. There was no effect of benazepril on plasma steady-state levels of either anticoagulants.