About 15% of patients with a Renal Cell Carcinoma (RCC) are also affected by a neoplastic thrombus of the Inferior Cava Vein (ICV). Improvement of perioperative cares techniques led to a decrease of mortality and morbidity. The oncological advantages arising from an en-bloc excision of the thrombus and of the primary tumor, even in presence of a distant metastases, have been well documented. Nevertheless surgical control of the intra-hepatic ICV remains a major technical topic for surgeons. If possible a satisfactory control of the ICV reduces blood loss and avoids tumour fragmentation possibly determining massive pulmonary embolisms. In the present paper we report our experience in surgical treatment of patients with RCC and caval neoplastic thrombus. From January 1996 through December 1998 40 patients with RCC have been observed at our Institution. All patients underwent radical excision of the tumor consisting of radical nephrectomy (n. 37 pts) or hemi-nephrectomy (2 pts). In seven cases (17.5%) caval extension was present. Infra-(Level I), intra-(Level II) and sovra-hepatic (Level III) involvement of the ICV was present in 3, 3 and 1 patient respectively. A concomitant distant metastases was present in one patient (a 2 cm left-lung lesion radically resected). All patients underwent cavotomy with excision of the thrombus. In case of intra-or sovra-hepatic caval extension (4 pts) an original surgical technique was used to remove the thrombus. The procedure can be described as follows: (1) transabdominal radical nephrectomy; (2) isolation of the controlateral renal vein and of the proximal tract of the ICV up to the iliac confluence; (3) section of the falciform and triangular ligaments; (4) execution of the Pringle manoeuvre; (5) section of the Spigelio vein and of all the sovra-hepatic accessory veins; (6) complete overturning of the liver; (7) clamping of controlateral renal vein and of proximal and distal ICV (sovra-hepatic or intra-thoracic); (8) cavotomy and radical thrombus excision; (9) suture of the ICV and prompt declamping of the vascular structures. The patient with Level III caval involvement presented also an atrial thrombus. He therefore underwent atriotomy and thrombus removal with cardioplegia, extracorporeal circulation and iliac-superior cava vein by-pass. Mean time of thrombus removal was 20 minutes. Blood loss consisted of 300 ml (100-500 ml). Intra-and postoperative mortality were absent. Major morbidity occurred in one patient (14.2%) (a case of perforated duodenal ulcer). Minor morbidity occurred in one patient (14.2%). Mean time of postoperative hospital stay was 8 days (5-20 days). After a mean follow-up of 20.5 months (1-40 months) all patients are alive and free of disease. It has been assessed that survival of patients with a RCC is not affected by the presence of a caval thrombus if radically resected. An en-bloc surgical removal is now a possible and safe therapeutic option. Nevertheless an inadequate control of the ICV in presence of an intra-or sovra-hepatic extension determines an increase of blood loss and the potential occurrence of lethal pulmonary embolisms. A complete isolation of the intrahepatic ICV, as described in this paper, is a safe and quick manoeuvre. In our experience its use can allow to achieve a complete control of the ICV with reduction of the blood-loss and radical thrombus excision.