From July 1969 to May 1994, radical prostatectomy was performed in 630 patients with clinically localized prostate cancer at the Department of Urology, University of Würzburg Medical School. These included 74 patients subsequently followed up for 15 years or more 15 years (15-23 years, mean 17.5 years), who were the subjects of the present study. Of these 74 patients 59 had pT2 tumors and 10 had pT3 tumors according to the staging criteria of the 1992 edition of the UICC TNM classification. The remaining 5 patients had microscopic lymph node metastases detected at staging pelvic lymphadenectomy (stage pT2-3pN1-2). Patients with lymph node involvement were treated by immediate orchiectomy. All other patients received no further treatment until progression occurred. The overall 15-year survival rate actually observed the 74 patients was 50% (37/74) and the disease-free survival rate was 43.2% (32/74 pts). Stage-related overall and disease-free survival rates were found to be 54.2% and 49.1%, respectively, for patients with pT2 tumors, 40% and 30% for those with pT3 tumors, and 20% and 0 for patients with lymph node metastases. Progression (either local recurrence or distant metastatic spread) was noted in 22 of the 74 patients (29.7%) within the 15-year period following radical prostatectomy. Mean time to progression was 7.9 years (3 months to 17 years). Within the follow-up period, 17 patients (23%) died of prostate cancer. These actual 15-year follow-up data show radical prostatectomy to be the most effective means of achieving long-term disease-free survival, if not cure, in patients with clinically localized prostate cancer.