In a patient with congenital absence of the uterus, daily measurements of progesterone (P), 17-hydroxyprogesterone (17-P), pregnenolone (Δ5P), 17-hcdroxypregnenolone (17-Δ5P), dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEA-S), testosterone (T), dihydrotestosterone (DHT), androstenedione (A), estrone (E1), estradiol-17β (E2), and cortisol (F) were performed over a period of 48 consecutive days. Serum P, 17-P, and E2determinations revealed normal, cyclical ovarian activity consisting of two luteal phases and one follicular phase. Serum E1, Δ5P, and DHEA-S levels were normal throughout the study, whereas DHEA and DHT levels were persistently elevated. Serum levels of 17-.Δ5P and A showed peak levels above normal. Serum T and F concentrations were normal during the initial part of the study, but some elevation was seen during the second luteal phase. In the patient studied, absence of the uterus did not seem to interfere with cyclic ovarian activity. The role of the uterus in the metabolism of androgens remains subject to further investigation.