Testosterone secreting adrenal adenoma is rare. We recently experienced a 17‐year‐old pubertal girl who showed signs of virilization and a high serum level of testosterone. The excised adrenal gland showed a 3.5 × 3 × 3‐cm cortical adenoma. Light and electron microscopic findings together with the high serum level and high tumor tissue contents of testosterone and dehydroepiandrosterone (DHA) indicated that the tumor was a testosterone‐secreting adrenal cortical adenoma. This appears to be a rather rare tumor from a review of the literature. Interestingly, in this case, the cytoplasm of the tumor cells contained structures resembling spironolactone bodies. From the results of enzyme histo‐chemistry, the steroidogenetic pathways in this tumor were speculated. Acta Pathol Jpn 40: