Twenty-nine normal volunteers were subjected to manometric studies before and after intraesophageal infusion of 100-proof alcohol at doses of 80, 120, 160, and 200 ml, corresponding to 31.6, 47.4, 63.2, and 79.0 g, respectively, administered over a 15-min interval on separate days. Corresponding mean serum concentrations of alcohol were 58.9 +/- 2.8, 77.0 +/- 4.8, 97.0 +/- 13.9, and 117.3 +/- 5.0 mg per dl, respectively. Both esophageal and lower esophageal sphincter function were unaffected at serum concentrations of alcohol less than 70 mg per dl. In contrast, when the serum alcohol concentration was 117 mg per dl, esophageal and lower esophageal sphincter function was altered significantly. The amplitudes of esophageal peristaltic waves were probably decreased in the proximal and distal segments. The maximal lower esophageal sphincter pressure response to pentagastrin was reduced from 35.4 +/- 4.6 to 17.3 +/- 6.1 mm Hg (P less than 0.01). In addition, the lower esophageal sphincter pressure response to a protein meal was inhibited significantly. Neither propagation velocities or esophageal contractions nor resting lower esophageal sphincter pressures were changed by the administration of alcohol at any of the doses tested.