Animal studies as well as clinical studies have suggested that the brain 5-HT system is important for the regulation of voluntary ethanol intake and preference. Previous studies have suggested that 5-HT1A receptor agonists may reduce ethanol preference in rats. In the present study on mice, the 5-HT1A receptor agonists (8-OH-DPAT), ipsapirone, and buspirone all antagonized the locomotor activity (LMA) stimulatory effect of ethanol (2.5 g/kg). The present results provide further support for the notion that the LMA-increasing effect of ethanol may be homologous to its reinforcing properties and that 5-HT1A receptor agonists may counteract these properties as well.