Between 1969 and 1976, 92 patients with proved prostatic carcinoma in stages T0 and T4 underwent pelvic lymphadenectomy. Median followup has been 43 months. All patients had normal serum acid phosphatase levels and no clinical evidence of metastases as determined by physical examination, bone scans and metastatic bone surveys. Pelvic lymph node metastases were noted in 32 cases. Radical prostatectomy was done in 34 cases and 45 patients received radiotherapy, 11 of whom had 125iodine seeds implanted. Progression of the neoplastic process, almost exclusively in the form of bony metastases, occurred in 18 of the 32 patients who had positive pelvic nodes and in 6 of the 60 patients with negative nodes (p less than 0.001). Patients with poorly differentiated carcinoma were more likely to have progression of the disease than those with moderately differentiated carcinoma (p less than 0.01) and no patient with a well differentiated carcinoma had disease progression.