Background. Laparoscopic adrenalectomy (LA) has become the preferred method of removal of most adrenal neoplasms, but few studies have evaluated the functional outcomes of this approach. The purpose of this study was to analyze our operative results and the clinical and biochemical responses to LA in patients with various hormonally active adrenal tumors. Methods. From 1993 through November 2000, 72 patients with functional adrenal tumors underwent attempted LA. Data were obtained retrospectively by review of medical records, during routine follow-up, and by patient questionnaire. Results. Indications for adrenalectomy were pheochromocytoma (n = 35), aldosteronoma (n = 29), cortisol-producing adenoma (n = 5), and adrenocorticotropic hormone-dependent Cushing's syndrome (n = 3). LA was completed in 70 of 72 patients, with 2 conversions (3%) to open adrenalectomy. Mean operative time for unilateral LA was 176 ± 60 minutes, and postoperative length of hospital stay averaged 3.0 ± 1.7 days. Complications, most of which were minor, occurred in 19% of patients; there were no serious complications or perioperative deaths. Two patients were unavailable for follow-up. At a mean follow-up interval of 37.6 months after LA (range, 2-90 months), resolution of clinical and biochemical signs of adrenal hyperfunction was accomplished in 34 of 34 patients with pheochromocytomas, 25 of 26 patients with aldosteronomas, 5 of 5 patients with cortisol-producing adenomas, and 3 of 3 patients with andrenocorticotropic hormone-dependent Cushing's syndrome. Two patients with multiple endocrine neoplasia (MEN) type 2 had contralateral pheochromocytomas removed 4 and 5 years after the initial surgery. Persistent hypertension necessitating medication was present in 72% of patients with aldosteronomas, although 92% of these patients had improved blood pressure control after LA. Recurrent hypokalemia developed in 1 patient (4%) with a cortical nodule in the contralateral adrenal. No local or distant tumor recurrences have occurred. Conclusions. LA results in an excellent clinical outcome in patients with various functional endocrine tumors. LA is associated with few major complications, and clinical and biochemical cure rates are comparable with those of open adrenalectomy during long-term follow-up.