Research has suggested that catalase plays a role in mediating ethanol's psychopharmacological effects. It has been shown that acatalasemic (C3H-A) mice differing in the activity of this enzyme consume larger amounts of ethanol. It has also been reported that when catalase activity is pharmacologically reduced, via 3-amino-1,2,4-triazole (AT), rats reduce their intake and preference for ethanol. The present research attempted to investigate AT's effects in nonselected mice. Swiss Webster mice were randomly assigned to groups of four per cage and further assigned to either a 5%, a 10%, or a 15% ethanol exposure condition. Mice were given a choice between water and increasing 1% concentrations of ethanol starting with 2%. Following five days of baseline, mice were injected daily with either AT (0.5 g/kg) or saline for five days. Results showed that AT significantly reduced ethanol consumption across treatment, but not posttreatment days. Results could not be explained by differences in total fluid intake. These results suggest a role for brain catalase in ethanol consumption across a variety of strains and species and further support the involvement of centrally formed acetaldehyde in the mediation of ethanol's psychopharmacological effects.