Adjuvant endocrine treatment of prostatic cancer is not an established method at present. With our knowledge of the mechanisms of endocrine dependence of human prostate cancer and of available clinical data, a beneficial effect on survival seems unlikely. It has been shown by several investigators that endocrine treatment has a more favorable effect on the primary tumor than on distant metastases, and local progression under endocrine management is seen less frequently than progression to distant metastases. Studies in patients with lymph node positive but otherwise locally confined prostate cancer have shown that time to progression can be delayed by a factor of 3 with early adjuvant endocrine treatment. Radical surgery and radiotherapy may be facilitated by preceding endocrine measures. There is, however, no evidence at present that initially inoperable tumors may become accessible to radical surgery or that preceding endocrine treatment improves the results of radical surgery. Such an effect appears to be unlikely unless one assumes that prostate cancer cells growing outside the prostate will disappear completely or retract into that organ, hypotheses that are not supported by clinical or experimental observations. It is unknown at present whether very early adjuvant treatment may prevent the progression and the promotion of focal disease to clinical prostate cancer. This possibility should be made a subject of future research.