Removal of a large extension of renal cell carcinoma into the inferior vena cava can be a difficult operation. Circulatory arrest is an operative technique that recently has been used to assist in resection of tumors that extend into the vena cava above the level of the hepatic veins. At our clinic 18 patients were operated on with the intent of using circulatory arrest during radical nephrectomy and inferior vena caval thrombectomy. Of the 18 patients 13 ultimately underwent this procedure, since the remaining 5 had unresectable tumors. One patient died intraoperatively of an adverse reaction to protamine after technically successful removal of the tumor and thrombus. Resection was successful in 12 patients and 9 remained free of disease with short followup. We believe that the addition of circulatory arrest during resection of a large inferior vena caval thrombus allows for an opportunity to resect the tumor in a controlled situation that reduces the potential for sudden massive blood loss or a major vascular injury, and ultimately makes the operation safer.