Laparoscopic adrenalectomy remains a controversial procedure for large tumors. We examined the outcome and complications of laparoscopic adrenalectomy for such lesions. A total of 178 patients underwent laparoscopic adrenalectomy, of whom 29 patients had large (>or =5 cm) tumors. Their mean age was 47.9 years (range 21-72 years), and the mean tumor size was 6.5 cm (range 5.0-11.0 cm). They were compared with patients whose adrenal tumors were <5 cm. The large-tumor group had a mean operating time of 176 +/- 48 minutes (range 84-278 minutes) and a mean blood loss of 136.6 mL (range 10-800 mL) and required a mean of 1.8 days before starting oral intake. None of these values is significantly different from the results in the control group (P > 0.05). The length of recovery was significantly longer in the large-tumor group (5.4 v 4.5 days; P < 0.05), but this was not true if a patient with a 23-day postoperative stay is excluded. The overall incidence of complications was 12% in the large-tumor group, which was not significantly different from that in the control group (P > 0.05). The operating time, blood loss, and incidence of complications after laparoscopic adrenalectomy did not differ between the patients with large and small adrenal tumors, indicating that experienced surgeons can safely and effectively use laparoscopy for larger tumors. However, it is necessary to consider carefully whether laparoscopic surgery is indicated for tumors that show infiltration on preoperative imaging or for patients who have undergone previous upper-retroperitoneal surgery.