PURPOSE: Major vascular injuries are uncommon but serious complications of laparoscopic surgery. Early recognition and conversion to an open procedure may be required to avoid further complications. We report 2 cases in which the vena cava was transected during retroperitoneoscopic nephrectomy, and review the literature. MATERIALS AND METHODS: All urological laparoscopic cases from 1993 to 2002 at 2 institutions were reviewed to identify major vessel transection. Two cases of inadvertent transection of the vena cava were identified. Medical records were reviewed for clinical and pathological information to identify factors leading to this complication. A MEDLINE search was performed to identify similar reports in the literature. RESULTS: Two patients at 2 institutions were identified with vena caval transection during retroperitoneoscopic nephrectomy. In both cases the vena cava was misidentified as a renal vein. The injury was recognized immediately in both cases and an open repair was performed by vascular surgery. Both patients recovered with no sequelae. In both cases a rotated camera on an angled laparoscope in addition to the relative lack of retroperitoneal landmarks may have contributed to a loss of orientation within the operative field. A similar report of an aortic transection was also found in the literature. CONCLUSIONS: Disorientation of the operating surgeon within the surgical field secondary to rotation of the camera lens and lack of retroperitoneal landmarks may contribute to vena caval transection during retroperitoneoscopic nephrectomy. This injury has not been found in transperitoneal nephrectomy, likely because more intra-abdominal landmarks exist, aiding in maintenance of orientation. Prompt intraoperative recognition and repair of the transection results in a favorable outcome.