Objective To establish a predictive model for postoperative complications in renal cell carcinoma patients with venous thrombus during hospitalization. Methods A total of 183 patients who underwent nephrectomy with venous thrombectomy between January 2012 and June 2020 in Department of Urology, Peking University First Hospital were enrolled and their perioperative data were retrospectively analyzed. Univariate and multivariate Logistic regression analyses were used to screen out risk factors of postoperative complications. A nomogram for predicting postoperative complications was developed by R Software. Discrimination of the predictive model was determined by calculating the concordance index (C⁃ index). The developed model was internally validated using enhanced Bootstrap method. Optimism⁃corrected performance was then calculated. Calibration of the model was evaluated by Brier score and calibration curve. Results The overall rate of postoperative complication during hospitalization was 36.6% (67/183) in this study. Multivariate Logistic analysis showed that higher Mayo level [odds ratio (OR)=2.27, 95% confidence interval (CI) 1.09−4.70, P=0.028], preoperative elevated transaminase (OR=8.62, 95%CI 1.88−39.57, P=0.006), preoperative acute normovolemic hemodilution (OR=2.50, 95%CI 1.05−5.94, P=0.039), use of cardiopulmonary bypass (OR=10.20, 95%CI 2.62−39.65, P=0.001) and higher maximum lactic acid value (OR=1.62, 95%CI 1.05−2.49, P=0.030) were the independent risk factors for postoperative complications, while male (OR=0.30, 95%CI 0.12−0.75, P=0.010) and a higher level of preoperative albuminemia (OR=0.90, 95%CI 0.82−0.98, P=0.020) were the protecting factors. Based on these independent factors, the nomogram was established with well discrimination of postoperative complications （C⁃index=0.837, 95%CI 0.776−0.899）. According to internal validation, the optimism⁃corrected C⁃index was 0.779 after optimism correction, with a corrected Brier score of 0.189. Conclusions The predictive model for postoperative complication is established based on male, preoperative albuminemia level, Mayo level, elevated transaminase, acute normovolemic hemodilution,use of cardiopulmonary bypass and maximum lactic acid value, with good discrimination and calibration ability, which is useful in clinical practice.