OBJECTIVE To compare perioperative outcome of transperitoneal and retroperitoneal approaches during laparoscopic radical nephrectomy (LRN) and to identify selection criteria for each approach. METHODS Over a 7-year period, 100 consecutive patients (median age 62 years, range 20-80) underwent LRN for a renal tumor with clinical stage T1a-T3a. The first choice approach was retroperitoneal. The transperitoneal approach was chosen in selected cases based on tumor characteristics. Thirty-three patients underwent the transperitoneal approach, and 67 had the retroperitoneal approach. Perioperative parameters including operative time, blood loss and complications and pathology data were retrospectively analyzed. RESULTS Overall, 33 transperitoneal laparoscopic radical nephrectomies (TLRN) and 67 retroperitoneal laparoscopic radical nephrectomies (RLRN) were carried out. There was a statistically significant difference between the two groups in terms of size (5.3 vs 3.0 cm, P < 0.0001) and clinical T stage (higher in the TLRN group, P < 0.0001) of the tumors. Intraoperative complications included bradycardia, pneumothorax, renal vein injury, and renal artery injury in the TLRN group, and pneumothorax in the RLRN group. There were no differences in terms of operative time, blood loss and tumor grade between the two groups. CONCLUSIONS Retroperitoneal and transperitoneal approaches yielded excellent surgical outcomes. The transperitoneal approach should be chosen based on tumor size and location to minimize vascular injury.