Objective: To review complications of robot-assisted partial nephrectomy (RAPN) at 5 centers, as classified by the Clavien system. Materials and Methods: A multi-institutional analysis of prospectively maintained databases assessed RAPN complications. From June 2007 to November 2011, 886 patients at 5 United States centers underwent RAPN. Patient demographics, perioperative outcomes, and complications data were collected. Complication severity was classified by Clavien grade. Results: Mean (standard deviation) data were patient age, 59.4 (11.4) years; age-adjusted Charlson Comorbidity Index, 3.0 (1.9); radiographic tumor size, 3.0 (1.6) cm; nephrometry score, 6.9 (2.0); and warm ischemia time, 18.8 (9.0) minutes. Median blood loss was 100 mL (interquartile range, 100-250 mL). Of the 886 patients, intraoperative complications occurred in 23 patients (2.6%) and 139 postoperative complications occurred in 115 patients (13.0%) for a total complication rate of 15.6%. Among the 139 postoperative complications, 43 (30.9%) were classified as Clavien 1, 64 (46.0%) were Clavien 2, 21 (15.1%) were Clavien 3, and 11 (7.9%) were Clavien 4. No complication-related deaths occurred. Intraoperative hemorrhage occurred in 9 patients (1.0%) and postoperative hemorrhage in 51 (5.8%). Forty-one patients (4.6%) required a perioperative blood transfusion, 10 (1.1%) required angioembolization, and 2 (0.2%) required surgical reexploration for postoperative hemorrhage. Urine leaks developed in 10 patients (1.1%): 3 (0.3%) required ureteral stenting, and 2 (0.2%) required percutaneous drainage. Acute postoperative renal insufficiency or renal failure developed in 7 patients (0.8%), 2 of whom required hemodialysis. The RENAL (radius, exophytic/endophytic properties of the tumor, nearness of tumor deepest portion to the collecting system or sinus, anterior/posterior descriptor and the location relative to polar lines) nephrometry scoring system accurately predicted RAPN complication rates. Conclusion: Complication rates in this large multicenter series of RAPN appear to be acceptable and comparable with other nephron-sparing modalities. Most complications (77.0%) are Clavien 1 and 2 and can be managed conservatively.