OBJECTIVE: To evaluate surgical and oncological outcomes after surgery in renal cell carcinoma (RCC) patients with inferior vena cava (IVC) tumor thrombus METHODS: A total of 58 patients from 2002 to 2019 underwent radical nephrectomy and IVC thrombectomy at Siriraj Hospital, Bangkok, Thailand, were retrospectively reviewed. Kaplan-Meier analysis was utilized to compare survival benefits between cohorts and Cox regression to evaluate predictors of patient survival. RESULTS: There were 5 (8.6%), 21 (36.2%), 23 (39.7%) and 9 (15.5%) patients with tumor thrombus level I, II, III and IV respectively. The major complications (Clavien 3-5) were observed in 15 patients (25.8%) and 80% were patients with high thrombus level (III-IV). There was 9% mortality (5 patients): 2 intraoperatively and 3 postoperatively. Median follow-up was 15 months (IQR:5-41). Two-year overall survival (OS) was 80% and 75% in all patients and pN0M0 cohort, respectively. There was significant difference in OS among each IVC thrombus level cohort (p<0.02). Two-year OS of metastatic RCC patients was 67% and not significantly different when compared to non-metastatic cohort (p=0.12). On multivariate analysis, only sarcomatoid dedifferentiation was associated with OS (p=0.04). Disease-free survival was not significantly different among thrombus-level cohorts (p=0.65). CONCLUSION: Our study suggested that surgical treatment for RCC with IVC thrombus provided acceptable OS outcomes, even in a small volume experience. Although the survival was significantly reduced with higher IVC thrombus level cohort, the level of thrombus itself was not an independent factor. Only sarcomatoid dedifferentiation was a predictor for OS after radical nephrectomy and tumor thrombectomy.