We studied 196 radical prostatectomy cases performed for clinical stage B prostate cancer with capsular penetration; in all cases seminal vesicles and lymph nodes were free of tumor. The mean followup in patients who showed no evidence of progression was 5 years. Focal capsular penetration was seen in 93 cases. There was no difference in progression in this group, irrespective of whether margins were negative or positive. High grade tumors (Gleason score 7 or more) had a significantly higher risk of progression compared to lower grade tumors (p = 0.0002). Established capsular penetration was seen in 103 tumors. Cancers with established capsular penetration had a higher risk of progression than those with focal capsular penetration. Established capsular penetration tumors were stratified into 3 groups with increasing risks of progression: 1) margins were negative and grade was low, 2) margins were positive or grade was high yet both adverse features were not present or 3) margins were positive and grade was high. The differences in progression among these 3 groups were statistically significant. Because of the negligible influence of positive margins in patients with focal capsular penetration the status of capsular margins should not influence the decision on whether to administer immediate postoperative adjuvant therapy. To evaluate the efficacy of adjuvant therapy following radical prostatectomy, tumors with capsular penetration should be stratified into groups having similar risks of progression according to the extent of capsular penetration, surgical margins of resection and grade.