The imidazobenzodiazepine, Ro15-4513, has been shown to antagonize some of the behavioral effects of ethanol (ETOH). In rats having relatively little experience in the open field, the actions of ETOH (0.75 g/kg IP), Ro15-4513 (1.25 mg/kg and 2.5 mg/kg, IP), and Ro15-4513 in combination with ETOH were measured on horizontal activity. Rats receiving ETOH showed a significant depression in horizontal activity. Doses of Ro15-4513 given alone produced no significant differences in activity from baseline levels. Rats pretreated with Ro15-4513 prior to receiving ETOH, however, showed a significant attenuation of the ETOH induced depression of activity. These results indicate that Ro15-4513 is effective in attenuating the depressive effects of ETOH in the open field in rats having little experience in the apparatus.