Objective： To evaluate the effectiveness and safety of radical nephrectomy and inferior vena cava thrombectomy in the treatment of patients with Mayo Ⅲ tumor thrombus, and to introduce our experience and surgical technique. Methods: The clinical data of 8 patients with Mayo Ⅲ tumor thrombus from October 2014 to September 2016 were analyzed retrospectively. Of the 8 patients, 3 were male and 5 were female. The average age was (50.8±18.7) years (18 to 77 years). The average body mass index (BMI) was (22.7±4.4) kg/m2 (15.2 to 30.8 kg/m2). Imaging suggested the right renal tumor in all the 8 cases. The average tumor size was (7.9±2.5) cm. Open radical nephrectomy and inferior vena cava thrombectomy was conducted in 5 cases and laparoscopic surgery in 3 cases, and 1 case was converted to open surgery. Results: All the 8 surgeries were completed successfully with no death case. The average surgery time was (370.3±101.6) min, ranging from 272-567 min. The average vena cava blocked time was (41.0±12.1) min, ranging from 17-55 min. The blood loss volume was (1 181.3±915.7) mL, ranging from 200-3 000 mL. During the operation, 5 cases were infused with suspended red blood cells, the amount of blood transfusion was 800-2 000 mL. 3 cases were infused of plasma with 400-1 000 mL. The average hospital stay was 9-23 d, with an average of (14.1±4.0) d. In the 8 patients, 4 cases underwent inferior vena cava wall resection because of invasion by tumor thrombus. Preoperative serum creatinine was 60-101 μmol/L, with an average of (76.4±15.3) μmol/L. Serum creatinine 1 week after the operation was 74-127 μmol/L, with an average of (100.8±21.1) μmol/L. Pathological diagnosis showed 6 cases of clear cell carcinoma, 1 case of papillary carcinoma type Ⅱ, and 1 case of Ewing’s sarcoma. Among the 8 patients, early postoperative complications occurred in 5 cases. Postoperative complications were graded as level Ⅱ, according to the Clavien classifications. The 8 cases were followed up for 2 to 24 months with an average of 11.3 months. There was 1 patient who suffered from lung metastasis. Conclusion: Our initial clinical results show that radical nephrectomy and inferior vena cava thrombectomy is safe and effective for patients with Mayo Ⅲ tumor thrombus. The wide extension of grade Ⅲ vein tumor thrombus leads to the difficulty of operation technique. Sufficient preoperative preparation, rich operative experience and skills can improve the safety of operation.