Plasma prolactin, luteinizing hormone and estradiol levels were determined in six normal adult females before and during a period of acute alcohol intoxication. Plasma hormone levels found in these studies were compared with values obtained after administration of an isocaloric beverage. Each woman served as her own control for both studies which were carried out on the same day of the menstrual cycle (day 8, 9 or 10) over two consecutive menstrual cycles. Integrated plasma samples were obtained every 20 min for 6 consecutive hr before acute alcohol administration and during the ascending, peak and descending portions of the blood alcohol curve. After acute alcohol administration, all women achieved a moderate degree of intoxication, with mean peak blood alcohol levels of 88 mg/100 ml. No significant differences in levels of luteinizing hormone and estradiol were detected during any phase of the blood alcohol curve when compared to prealcohol administration values. No significant differences were found between luteinizing hormone and estradiol after alcohol administration when compared with values obtained after isocaloric beverage. The only significant difference in hormone levels was a small elevation in prolactin during the descending phase of the blood alcohol curve when nausea and vomiting coincident with alcohol-induced intoxication occurred. These data contrast sharply with the significant effects of acute alcohol intake on pituitary gonadal hormones in normal human males.