The occurrence of tumors originating from aberrant adrenocortical tissue in ectopic site is very rare. Up to now only two cases of ectopic aldosterone-producing adenoma have been described. We have observed another case of ectopic aldosteronoma, located in the retrocaval region, laterally to the body of the 12th thoracic vertebra. This ectopic tumor was associated to another adrenocortical adenoma, in the adrenal gland of the same side. The diagnostic implications of this observation are discussed.