Several reports have demonstrated that acute lead acetate administration enhances brain catalase activity in animals. Other reports have shown a role of brain catalase in ethanol-induced behaviors. In the present study we investigated the effect of acute lead acetate on brain catalase activity and on ethanol-induced locomotion, as well as whether mice treated with different doses of lead acetate, and therefore, with enhanced brain catalase activity, exhibit an increased ethanol-induced locomotor activity. Lead acetate or saline was injected IP in Swiss mice at doses of 50, 100, 150, or 200 mg/kg. At 7 days following this treatment, ethanol (0.0, 1.5, 2.0, 2.5, or 3.0 g/kg) was injected IP, and the animals were placed in the open-field chambers. Results indicated that the locomotor activity induced by ethanol was significantly increased in the groups treated with lead acetate. Maximum ethanol-induced locomotor activity increase was found in animals treated with 100 mg/kg of lead acetate and 2.5 g/kg of ethanol. Total brain catalase activity in lead-pretreated animals also showed a significant induction, which was maximum at 100 mg/kg of lead acetate treatment. No differences in blood ethanol levels were observed among treatment groups. The fact that brain catalase and ethanol-induced locomotor activity followed a similar pattern could suggest a relationship between both lead acetate effects and also a role for brain catalase in ethanol-induced behaviors.