Alcohol-induced pseudo-Cushing's syndrome has been described in numerous case reports, yet the patients have been thoroughly evaluated in only a few cases and the prevalence of hypercortisolism in the alcoholic population is not known. We studied a group of 56 alcoholic men on admission to a detoxification ward using the overnight 1 mg dexamethasone suppression test as a screening test. Most (82%) had normal cortisol suppression, and of those who did not (18%), three of four who could be retested became normal within four days. A smaller group of 14 patients was evaluated with measurement of 24-hour urinary free cortisol, baseline plasma ACTH and serum cortisol measurements, and measurement of ACTH and cortisol after dexamethasone. One patient with sustained abnormal suppression of serum cortisol by dexamethasone (up to 18 days) also demonstrated a striking lack of suppression of plasma ACTH by dexamethasone, compared to the other alcoholics studied. The data obtained on this patient, as well as information obtained from published case reports, are consistent with the concept that alcohol-induced pseudo-Cushing's syndrome is a centrally mediated defect that occurs uncommonly in alcoholics.