A true hermaphrodite with a bilateral ovotestis and a 46 XX karyotype was studied. This 14-year old subject developed ambiguous puberty with bilateral gynecomastia and stage IV public hair. Relatively high level of testosterone (T) (2.80 ng/ml), was found. The 5 alpha-reductase activity for T in the pubic skin was similar to that observed in normal adult males. A hemorrhagic corpus luteum in the left ovotestis was observed at laparotomy. The luteal phase immediately after dexamethasone administration (1 mg/day for 7 days) was characterized by a significant decrease of plasma androgens, T and androstenedione (A). The constantly low level of T (0.30 ng/ml) during the luteal phase in this subject did not appear to be due to the previously administered dexamethasone. This decrease of T production in the luteal phase might be secondary either to the increase of the estradiol-17 beta (E2) secreted by the corpus luteum or to the decrease of LH levels. Both mechanisms might act concomitantly.