Background: Radical nephrectomy is the treatment of choice for large renal cell carcinoma (RCC). Objectives: To describe the complications after radical nephrectomy for suspected or proven RCC and analyze the risk factors. Materials and methods:We retrospectively reviewed medical records from 110 patients who underwent radical nephrectomy for RCC in our institution between January 2007 and December 2013. The clinicopathological data of all patients were recorded and complications were graded using modified Clavien classification. Univariate and multivariate analysis was made of the predictive factors for complications. Results: Fifty postoperative complications occurred in 34 patients (31%) within 30 days, including 11% transfusion related complications. There were 22% minor complications (6% grade 1, 16% grade 2) and 9% major complication (5% grade 3, 2% grade 4, and 2% grade 5). The most common complications were transfusion-related, re-laparotomy because of bleeding, and prolong ileus. In univariate analysis, pathological T-stage (P = 0.001), American Society of Anesthesiologists (ASA) score (P = 0.007), tumor size (P = 0.01), and tumor diameter >4 cm (P = 0.03) were significant predicting factors. Major Charlson comorbidity index (CCI >2) was the only significant factor for major complications (P = 0.04). In multivariate analysis, ASA score was a significant independent predictor for overall complications (odds ratio 4.83, P = 0.01). Conclusions: ASA score was a significant predictive factor for overall postoperative complications. Comorbidities was also a predictor for major complications in radical nephrectomy. Preoperative risk stratification for complications should be considered during decision-making and for proper counseling of patients.