The purpose of this study was to describe the development of the laparoscopic technique for anterior lumbar fusion and to evaluate the clinical results of a first case series of patients. The in vivo porcine model was used first to develop the technique of transperitoneal laparoscopic interbody fusion. Afterwards, operative time, blood loss, perioperative complications and length of stay were recorded for the first 34 patients who underwent laparoscopic fusion of L4-5 or L5-S1 at two medical centers in 1994. Laparoscopic lumbar fusion was successful in 30 of 34 patients. Four patients early in the series successfully were converted to an open procedure because of poor visualization (two cases) or iliac venous injury (two cases). Transfusion was required in one patient; average blood loss was 128 ml. Operative time averaged 218 min, hospitalization 3.67 days. Laparoscopic fusion is feasible and has minimal complications when a skilled laparoscopic surgeon is present for exposure. Minimal excisional trauma associated with this technique should result in decreased hospitalization and earlier recovery compared with standard open techniques. Preliminary results indicate an earlier discharge and return to work (3 weeks) than that expected for standard open techniques.