Acute effects of ethanol ingestion (1.0 g per kg body weight) on the serum levels of LH, FSH and prolactin were studied in 10 postmenopausal women. Ethanol was administered during the first 3 hr of the experiment and the hormone concentrations were monitored for 10 hr. Each subject served as her own control in an identical experiment without ethanol. Blood alcohol concentration reached its maximum 1.18 +/- 0.02 g/l (mean +/- S.E.M.) 3hr after the start of the drinking. No changes were found in the levels of LH and FSH during the experimental period. The increase of 80% in the mean concentration of prolactin at 4hr after the start of drinking was not statistically significant. On the basis of these and previous results we conclude that alcohol has no acute effects on the secretion of gonadotropins in women.