Peripheral serum levels of dehydroepiandrosterone (DHA) and its sulphate (DHAS), 4-androstene-3, 17-dione (A-4), 17 alpha-hydroxyprogesterone (17-OHP), cortisol and albumin were measured in patients with prostatic cancer before treatment and after orchidectomy or during combined oral and intramuscular oestrogen treatment. Orchidectomy caused a pronounced decrease in 17-OHP levels and minor but significant decreases in the levels of A-4 and DHAS. Dehydroepiandrosterone, cortisol and albumin were unaffected by treatment. Oestrogen treatment caused a pronounced decrease in the serum levels of DHA, DHAS, 17-OHP and A-4 and a small but significant decrease in serum albumin. Cortisol levels increased, probably due to elevated transcortin levels. The ratio of DHA to DHAS was unaffected by either orchidectomy or by oestrogen treatment. These results confirm that the testis contributes to circulating DHAS. The mechanism behind the more pronounced decrease in adrenal androgens during oestrogen treatment is not known but, for DHAS, increased metabolic clearance due to the decrease in albumin levels may contribute in this respect. The unchanged values for the ratio of DHA to DHAS indicate that this sex-specific sulphatase/sulphotransferase balance is insensitive to endocrine manipulations in adult men. The results further invalidate the hypothesis that there is a 'compensatory' increase in adrenal androgen output following orchidectomy.