To evaluate the feasibility and outcome of laparoscopic-assisted radical nephrectomy and inferior vena cava (IVC) tumor thrombectomy in patients with renal cell carcinoma and level I IVC tumor thrombus. The clinical, operative, and pathologic data were retrospectively obtained from patients undergoing the above-mentioned procedure for renal tumors involving the IVC. This approach involved laparoscopic dissection of the kidney and renal vasculature/IVC. After renal artery ligation, an 8 to 12-cm incision was made from the tip of the 11th rib extending anteriorly toward the midline. Through this incision, a Satinsky vascular clamp was placed on the IVC in such a way as to include all the caval thrombus. The tumor thrombus was removed en bloc with the kidney and the cavotomy repaired with a running suture. Four obese patients underwent transperitoneal laparoscopic-assisted right nephrectomy with inferior vena cava (IVC) thrombectomy. The mean tumor size was 9 cm (range 6 to 13), with the thrombus extending 2 cm into the IVC in all cases. Patients had a mean body mass index of 32.8 (range 30.5 to 37.2) and a mean American Society of Anesthesiologists score of 2.8 (range 2 to 3). The mean operative time was 248 minutes (range 225 to 274). The mean estimated blood loss was 517 mL (range 250 to 900). No intraoperative or postoperative complications occurred. The mean hospital stay was 6.2 days (range 4 to 11, median 5). Laparoscopic-assisted nephrectomy and IVC thrombectomy is a difficult but feasible procedure. This approach allows a smaller incision than a typical open approach. Additional studies are needed to examine the advantages of this approach over a pure open approach.