Swimming behavior in the mouse was used to study the motor disturbances induced by alcohol, and the effects of vitamin C upon these disturbances were assessed. High doses of vitamin C (125 and 500 mg/kg) prevented any swimming impairment due to ethanol; however, lower doses of vitamin C (62.5 mg/kg) had no significant effect. When given 1 h before alcohol, the protective effect of vitamin C was reduced. The alcohol-induced intoxication lasted beyond alcohol's elimination from the blood, suggesting that the intoxication is maintained by a metabolite of ethanol or by an effect of ethanol, or a metabolite, on another metabolic system.