We reviewed our institutional experience with primary hyperaldosteronism to compare clinical outcomes after laparoscopic versus open adrenalectomy. All patients surgically treated for primary hyperaldosteronism from 1988 through 1999 are included in this study. Patients were assigned to either the LA (laparoscopic) or OA (open) group depending on the initial surgical approach selected for treatment. Records were reviewed to determine demographics, operative results, and complications. Twenty-four patients were surgically treated for primary hyperaldosteronism. There were no significant differences between groups with respect to age, weight, number of preoperative antihypertensive medications, or preoperative potassium level. The results of adrenalectomy with respect to number of postoperative antihypertensive medications or serum potassium level were also similar. Operative times were not significantly different (191 +/- 53 minutes for OA and 205 +/- 88 minutes for LA) between groups, but four LA patients were converted to OA. Estimated blood loss was 401 +/- 513 cm3 for OA and 127 +/- 131 cm3 for LA (P = 0.07). Hospital length of stay was 6.7 +/- 3.7 days for OA and 3.3 +/- 2.7 days for LA (P = 0.02). Complications were nine for OA and three for LA (P = 0.001 by Pearson's Chi square). LA is similar to OA in the treatment of primary hyperaldosteronism. The significantly fewer complications and shorter length of hospital stay associated with LA makes the laparoscopic approach the preferred method for treating primary hyperaldosteronism.