The peripheral levels of pregnenolone (δ3-p), 17-hydroxypregnenolone (17-δ3-P), progesterone (P), 17-hydroxyprogestcrone (17-P), testosterone (T), 5α -dihydrotestosterone (DHT), androstencdione (A), dehydroepiandrostcrone (DHEA), its sulfalc (DHEA-S), estronc (E2), estradiol-17β (E2), and cortisol (F) were measured prior to and 11/2 and 9 months after removal of a right adrenal “compact cell” adenoma in an amenorrheic patient with a virilizing adrenal adenoma, under the following conditions: 1) control for 2 days, 2) dexamethasonc, 0.5 mg, every 6 hours for 2 days, and 3) dexamclhasonc, 2 mg, every 6 hours for 2 days. Except for E2, E2, and F, the control levels of ail steroids measured were elevated, markedly so for δ3-P, 17-δ3-P, DHEA, A, and DHEA-S. Dexamethasonc treatment had no detectable effect on the steroid levels. Following removal of the adrenal adenoma, the levels of all steroids returned to normal. The patient became cumenorrheic, with marked improvement of her hirsutism and virilization.