Purpose: To evaluate a case of a normal estrogenic woman with amenorrhea and polycystic ovarian syndrome who fails to get menses after progesterone withdrawal but who menstruates with oral contraceptives. Methods: The following sera assays were obtained: total testosterone (T), free T, weakly bound T, dehydroepiandrosterone sulfate, 17 hydroxyprogesterone, estradiol, free thyroxin, thyroid stimulating hormone, prolactin, evening cortisol, LH and FSH. Results: The total testosterone was markedly elevated but the free testosterone was normal and the free and weakly bound testosterone was the high end of normal. The LH/FSH ratio was markedly increased consistent with the ultrasound findings of polycystic ovarian syndrome. Vaginal cytology showed a mixed high estrogen/high androgen effect and the endometrial thickness was only 5 mm. Twice she failed to have menses following progesterone withdrawal. Conclusions: One hypothesized mechanism is that the high testosterone levels even though mostly in the bound form inhibited estrogen from causing adequate endometrial development.