Pretreatment plasma concentrations of total testosterone (T), sex hormone binding globulin binding capacity (SHBG), T/SHBG ratio, and free testosterone (fT) were measured in 123 patients with prostatic cancer categorized into groups according to the UICC classification. The patients were randomized to orchiectomy or estrogen therapy and the mean follow-up time was 48 months. The mean plasma levels of T were higher in patients without metastases and with intracapsular cancer, but the differences were not statistically significant. The calculated ratio of T/SHBG was noticed to be significantly higher (p < 0.05) in the M0 category. The prognostic significance of pretreatment T and, more impressively, T/SHBG ratio and fT was confirmed. Low pretreatment values indicated poorer prognosis. This study supports the view that there are differences in the pretreatment T and fT levels in prostatic cancer patients in relation to the stage of tumor and that these hormone assays could be used as prognostic factors.