PURPOSE: This study comparedthe effectiveness and safety of laparoscopic adrenalectomy with conventional open adrenalectomy for the treatment of pheochromocytoma. METHODS: Medical records of 100 patients who underwent surgical removal of pheochromocytoma (open adrenalectomy, n=59; laparoscopic adrenalectomy, n=39) at Samsung Medical Center from June 1995 to August 2007 were retrospectively reviewed. RESULTS: To draw an appropriate comparison, patients with a tumor less than 7 cm in size were evaluated (open adrenalectomy, n=23; laparoscopic adrenalectomy n=31). No statistically significant differences were evident according to age, gender and tumor size. The mean operating time was 158 min for the open surgery group and 114 minfor the laparoscopic group (P<0.01). The mean postoperative hospital stay was 10.4 days following open surgery and 5.6 days following laparoscopic surgery (P<0.01). The mean volume of the estimated blood loss for the laparoscopic surgery group (482 ml) was less than for the open surgery group (mean 229 ml) (P=0.06), and the time to first oral intake was 1.7 days after laparoscopic adrenalectomy and 3.5 days after open surgery (P<0.01). The frequency of using analgesics for postoperative pain after laparoscopic adrenalectomy was markedly lower than following conventional open adrenalectomy. There was no recurrence or complications during the follow-up periods (mean: 30 months). CONCLUSION: Laparoscopic adrenalectomy offers advantages of less postoperative pain, shorter operative time and a shorter hospital stay as compared with conventional open adrenalectomy. Laparoscopic adrenalectomy for treating pheochromocytoma is a minimally invasive alternative to conventional open adrenalectomy.