Naloxone, 7,8-dihydro-14-hydroxynormorphinone, and N-allyl-7,8-dihydro-14-hydroxynormorphine have been idenfied in a human urine specimen after naloxone administration. The metabolites were isolated, after hydrolysis with glusulase, by column chromatography and identified by TLC and spectrofluorimetry. These findings indicate that both N-dealkylation and the reduction of the 6-keto group of naloxone as well as glucuronide formation occur in man. Evidence is also presented indicating that N-allyl-7,8-dihydro-14-hydroxynormorphine formation occurs in rabbits as well as in man and the chicken.