In this study, we assessed biochemical outcomes after robot-assisted radical prostatectomy (RARP). Between July 2005 and November 2007, one hundred and seventy-six consecutive patients treated by RARP without neoadjuvant treatment were included in this study. All procedures were performed by a single surgeon and the median follow-up period was 60 months (interquartile range (IQR): 59-69). The median prostate specific antigen was 7.50 ng ml 21 (IQR: 5.14-11.45) and 39.2% of the patients were classified as intermediate risk and 15.3% were classified as high risk; on final pathological examination, 35.2% of the patients had non-organ confined disease and 37.5% and 14.2% had Gleason scores of 7 and 8-10, respectively. The biochemical recurrence (BCR)-free survival rates at 3 and 5 years were 85.6% and 81.2%, respectively. The 5-year BCR-free survival rates stratified by pathologic Gleason scores were 93.1% in Gleason scores of 6 or less, 74.5% in a Gleason score of 7, and 58.1% in Gleason scores of 8 or greater, respectively (P,0.001). When stratified by pathologic stage, the BCR-free survival rates were 89.8% in pT2 patients, 66.2% in pT3a patients, and 39.3% in pT3b patients at 5 years following RARP, respectively (P,0.001). Preoperative prostate-specific antigen (PSA), pathologic stage, postoperative Gleason score and surgical margin status were independently associated with BCR in multivariate analysis. In this study, we report biochemical outcomes after RARP with the longest follow-up periods to date in Asian men. We found that robotic surgery provided satisfactory biochemical outcomes, and that RARP is a safe and effective procedure in terms of oncologic outcomes.