The oral administration of 1,4-butanediol (1,4-BD) at doses ranging from 100 to 300 mg/kg, twice daily, produced a dose-dependent reduction (40 to 85%) in the voluntary ethanol intake in rats selectively bred for high preference for ethanol. Treatment with 1,4-BD did not reduce total fluid intake. Repeated 1,4-BD administration (300 mg/kg twice daily for 7 days) suppressed ethanol intake almost completely. After suspension of 1,4-BD treatment, the inhibitory effect on ethanol intake remained significantly low for 2 days. 1,4-BD failed to inhibit aldehyde dehydrogenase to a concentration of 10 mM in rat liver homogenate.