A comparison was made between the efficacy of dopamine-.beta.-hydroxylase and/or aldehyde dehydrogenase inhibition in suppressing voluntary ethanol consumption in rats. Calcium carbimide, which caused the largest increase in blood acetaldehyde levels following ethanol injections, was the least effective in reducing ethanol consumption; FLA-63 [bis(4-methyl-1-homopiperazinylthiocarbonyl)disulfide], which had a smaller effect on blood acetaldehyde levels, was the most potent suppressor of ethanol ingestion. Disulfiram, which inhibits both aldehyde dehydrogenase and dopamine-beta-hydroxylase, had an intermediate effect in terms of raising blood acetaldehyde levels and in suppressing ethanol intake. The inhibition of dopamine-beta-hydroxylase may be at least partly responsible for the suppression of ethanol intake following disulfiram administration, and disruption of catecholamine synthesis may be a more effective method for suppressing ethanol consumption.