Objective: To investigate the prognostic significance of positive surgical margins (PSM)s among patients who underwent radical prostatectomy (RP) for pT2 and pT3a prostate cancer. Patients and methods: We reviewed the records of 658 patients who were revealed to have pT2 and pT3a prostate cancer after undergoing RP without neoadjuvant or adjuvant treatment. For our analysis, patients were subgrouped as the following: group 1: 406 (61.7%) with negative surgical margins (NSM)s and no extracapsular extension of tumor (ECE); group 2: 99 (15.0%) with PSMs and no ECE; group 3: 63 (9.6%) with NSMs and ECE; and group 4: 90 (13.7%) with PSMs and ECE. The effects of various variables on biochemical recurrence (BCR)-free survival were assessed via uni- and multivariate analyses. Results: During median follow-up of 36 months, group 1 had significantly higher BCR-free survival compared with the other 3 groups (P 0.001). However, no significant differences in BCR-free survivals were observed among the group 2, 3, and 4 (all P 0.05). In multivariate analysis, PSM (P 0.009) was observed to be significantly associated with BCR-free survival among groups 1 and 2 combined. Among groups 3 and 4, pathologic Gleason score (P 0.002), but not PSM (P 0.668), was the only significant predictor for BCR-free survival in multivariate analysis. Conclusions: According to our results, PSM is significantly associated with biochemical outcome after RP in pT2 prostate cancer. Meanwhile, patients with pT2 tumor and PSM appear to have comparable biochemical outcome compared with those with stage pT3a tumor