This study compares the outcome of laparoscopic adrenalectomy (LpA) in 23 patients using CO2 insufflation with the outcome of this procedure in another 8 patients with pheochromocytoma (7 unilateral, 1 bilateral) using helium for pneumoperitoneum. The adrenal lesions in the first group included nonfunctional adenoma (n = 3), aldosterone adenoma (n = 11), Cushing's adenoma (n = 6), and Cushing's disease (n = 3). The latter patients were compared with a third group of 8 patients with pheochromocytoma undergoing conventional transabdominal adrenalectomy (CTA). With both procedures, intraoperative changes in plasma catecholamine levels were studied during pheochromocytoma removal and the changes correlated with intraoperative cardiovascular derangements. LpA was successfully performed in 95% of patients with adrenal lesions and in 100% of patients with pheochromocytoma. There was no significant difference in laparoscopic adrenalectomy for pheochromocytoma compared to that for other adrenal lesions in terms of operative time, blood loss, hospital stay, analgesic requirements, and return to normal activity. The outcome was less favorable in pheochromocytoma patients undergoing CTA. The largest increase of catecholamine levels in pheochromocytoma patients occurred during tumor manipulation with both LpA (17.4-fold for epinephrine and 8.6-fold for norepinephrine) and CTA (34.2-fold for epinephrine and 13.7-fold for norepinephrine), but cardiovascular instability was associated only with CTA. LpA may become the technique of choice for surgical removal of adrenal lesions and may also become the preferred method for removing pheochromocytoma.