Optical resolution of (+)-N-cyclopropylmethyl-3-hydroxy-9-azamorphinan (I) was successfully effected with (+)-O, O-dibenzoyltartaric acid or (2R : 3R)-2'-nitrotartranilic acid as the resolution agent. The optically active compounds thus obtained were tested for their analgesic activity and antagonistic effect of morphine analgesia.