OBJECTIVE To develop and assess the feasibility of laparoscopic partial nephrectomy performed using the daVinci robotic system. METHODS Between November 2002 and August 2003, 13 patients with solid or suspicious cystic renal masses underwent robotic-assisted laparoscopic partial nephrectomy. In 8 cases, an intra-arterial catheter was inserted for renal cooling before occlusion of the renal artery. The remaining 5 patients underwent partial nephrectomy after the renal hilum had been clamped. Tumor excision and intracorporeal suturing were performed entirely with telerobotics. The perioperative data and pathologic results were retrospectively reviewed. RESULTS The mean lesion diameter was 3.5 cm (range 2.0 to 6.0). The mean operative time was 215 minutes (range 130 to 262), and the mean blood loss was 170 mL (range 50 to 300). The mean warm ischemia was 22 minutes (range 15 to 29), and the mean cold ischemia time was 33 minutes (range 18 to 43). The length of hospital stay averaged 4.3 days (range 2 to 7). The resected lesions included renal cell carcinoma in 10, oncocytoma in 2, and a complex renal cyst in 1. In 1 case, a positive margin occurred despite negative frozen sections; laparoscopic nephrectomy was performed and showed no residual tumor. One patient experienced postoperative ileus. At 2 to 11 months of follow-up, no recurrence had been observed. CONCLUSIONS Robotic-assisted partial nephrectomy is feasible. Robotic partial nephrectomy can be safely performed using a transperitoneal or retroperitoneal approach. A second scrubbed assistant is mandatory to provide assistance using conventional laparoscopic instruments with this technique.