The fate of 48 patients with clinical stage T3 prostatic carcinoma after attempted curative surgical management was studied. In 23 of these patients positive frozen sections of the lymph nodes were found at pelvic lymphadenectomy and orchiectomy was performed. The median interval to progression was 61 months. Radical prostatectomy was performed in the remaining 25 patients. In 4 of these patients positive lymph nodes were found on paraffin sections but no additional treatment was given. Over-all, total tumor removal as defined by negative lymph nodes and negative margins of resection could be achieved in 14 of the 48 patients (29 per cent). During the same period 34 patients with clinical state T less than 3 prostatic carcinoma were treated in a similar manner. Orchiectomy was done in 4 patients because of positive frozen sections of the lymph nodes and radical prostatectomy was done in 30, including 1 in whom positive paraffin sections of the lymph nodes were found but no additional treatment was given. An attempt was made to study the impact of several prognostic factors by comparing the probability of progression between patients with stage pT3 disease with (T3pT3N0) or without (T less than 3pT3N0) extracapsular tumor growth as determined by preoperative rectal examination (36 versus 27 per cent progression at 3 years), with or without positive margins of resection (45 versus 20 per cent progression at 3 years) and with or without involvement of the seminal vesicles (47 versus 18 per cent progression at 3 years). Our results suggest that a certain proportion of patients with clinical stage T3 disease will benefit from radical prostatectomy. This is to be expected especially in patients with stage T3pT3N0 cancer and negative margins.