Background. Adrenocortical carcinoma (ACC) that produces aldosterone is an extremely rare, uncharacterized endocrine malignancy. Our aim was to characterize this neoplasm in terms of its clinical behavior and patient outcomes. Methods. A retrospective review was made of all patients who had operative management of aldosterone-secreting ACC from 1957 to 2000 at the Mayo Clinic. Comparisons were made to patients with non-aldosterone-secreting ACC treated during the same period. Results. Of 141 patients with ACC, we identified 15 patients with aldosterone-secreting ACC. Isolated aldosterone hypersecretion was present in 10 patients, and mixed hormonal secretion was detected in 5. Mean tumor size and weight were 10.8 cm and 453 g, respectively. Surgical management included curative resection in 10 patients (67%). Perioperative mortality was 20%. Disease recurred in 7 patients (70%) with a median interval of 17 months. Five-year survival was 52%. Patients with aldosterone-secreting ACC had an increased risk of perioperative mortality (20% vs 5%), yet they had an overall survival of 63 months compared to 19 months for patients with non-aldosterone-secreting ACC. Conclusions. Aldosterone hypersecretion occurs in 11% of all ACCs and is associated with unique operative risk and outcome. Although patients harboring aldosterone-secreting ACC appear to have an increased risk of perioperative death, survivors may have an improved overall survival rate compared with patients with non-aldosterone-secreting ACC.