In humans, the action of ethanol on gastrin release is still unclear and that of alcoholic beverages greatly unknown. The effect of a drink of various concentrations of pure ethanol and several commonly ingested alcoholic beverages on plasma levels of immunoreactive gastrin in 6 healthy human volunteers were studied and compared to a protein-rich meal. A drink of distilled water (250 ml) and of pure ethanol (250 ml or 125 ml in the case of 40% vol/vol ethanol) in concentrations (4, 10, 20 and 40% vol/vol) normally present in beer, wine, liquor and whiskey did not stimulate plasma gastrin levels above basal levels. Of the alcoholic beverages given only whiskey (125 ml) did not stimulate gastrin release. Beer or red and white wine (250 ml each) caused a rapid increase in plasma gastrin concentrations with a peak at 15-20 min, basal levels being reached 60 min after starting the drink. The 60 min integrated plasma gastrin response to beer or red and white wine was .apprx. 50% of the gastrin response to the protein-rich (steak) meal (883 .+-. 297 pmol.cntdot.min.cntdot.1-1; mean .+-. SE). A drink of 250 ml white wine together with the meal did not cause a significantly higher integrated gastrin response than the protein meal with 250 ml of distilled water. Commonly ingested alcoholic beverages such as beer or red and white wine, but not whiskey, were potent stimulants of gastrin release in humans. The ethanol content of these beverages was not responsible for the increase in plasma gastrin levels, since oral ingestion of pure ethanol in equivalent concentrations and amounts did not elicit a rise in plasma gastrin levels. Some unknown ingredients present in beer and wine were most likely responsible for the gastrin release by alcoholic beverages.