A clinical syndrome combining hypertension and hypokalemic alkalosis led to the diagnosis of primary hyperaldosteronism, caused by a right-sided, 2 cm large, apparently benign aldosterone-producing adenoma. The adrenal tumor was completely resected by laparoscopic adrenalectomy. Six months after surgery, the patient exhibited a severe relapse of hyperaldosteronism. Extensive peritoneal metastases of a mixed aldosterone- and cortisol-secreting adrenocortical carcinoma were found at abdominal laparotomy. In the light of this case report, we discuss the possibility that laparoscopic resection of adrenocortical tumors might contribute to their subsequent peritoneal dissemination.