The levels of plasma dehydroepiandrosterone (DHEA), androst-5-ene-3 beta,17 beta-diol (delta 5-diol), testosterone (T), dihydrostestosterone (DHT), androstane-3 alpha,17 beta-diol (3 alpha-diol), androsterone (ADT), and the related glucuronide (G) derivatives were determined in intact and castrated men with prostatic cancer. The plasma concentrations of DHEA and DHEA-G were not significantly different in intact and castrated men while delta 5-diol as well as delta 5-diol-G were 50% lowered in castrated men. As expected, T and DHT concentrations were markedly lower in castrated men. These low plasma levels of T and DHT were accompanied by a decrease of 3 alpha-diol, ADT, T-G, 3 alpha-diol-G, and ADT-G levels. There was, in unoperated men, a positive correlation between the levels of DHEA and ADT-G as well as DHEA and DHEA-G, while T values were highly correlated with ADT-G and 3 alpha-diol-G levels. Furthermore, a significant relationship was found between DHEA and ADT-G as well as 3 alpha-diol-G in castrated men. Our data clearly demonstrate that ADT-G and 3 alpha-diol-G levels are more affected by castration than are the corresponding unconjugated steroids and suggest that these steroid glucuronides should be good markers of androgen metabolism. Moreover, the significant relationship between DHEA, ADT-G, and 3 alpha-diol-G in castrated men also suggests that approximately 30% of C-19 steroids from the adrenals are converted to T and DHT, which are further transformed into steroid glucuronides.