Introduction. In the United States and Europe, the retroperitoneoscopic approach to renal surgery has generally been less popular than the transperitoneal laparoscopic approach, primarily because of its "smaller" working space and surgeons' relative unfamiliarity with the optimal operative technique. Presented herein are our current techniques, developed in more than 400 retroperitoneoscopic renal procedures at two major centers performing urologic laparoscopic surgery. Technical Considerations. Creation of an adequate working space in the retroperitoneum outside of, and posterior to, Gerota's fascia is a critical first step. At one institution, this working space is created with a balloon dilator; at the other, finger dissection is employed for this purpose. A longitudinal incision is made in Gerota's fascia, parallel and close to the psoas muscle, to access the renal hilum. During nephrectomy, the renal hilum is approached initially, followed subsequently by mobilization of the specimen. Conclusion. Retroperitoneoscopy allows superb, early access to the renal hilum while avoiding the peritoneal cavity, and is our preferred approach for performing most laparoscopic renal surgery, including radical nephrectomy for cancer. The techniques we describe have made retroperitoneoscopy a dependable, user-friendly, and routine approach for minimally invasive surgery of the kidney at our two centers. (C) 1999, Elsevier Science Inc.