This study shows that a moderate dose of alcohol (0.62 g/kg) can impair cognitive processes controlling behavioral inhibition and flexibility (i.e., inhibiting one response and making a different one). Two groups of male social drinkers (n = 8) received alcohol or a placebo and performed two change tasks that required high or low information processing. Results showed that alcohol impaired inhibitory control and response flexibility following a failure to inhibit a first response, and the intensity of impairment did not differ under the two information processing conditions. Response reaction time and accuracy were not affected by alcohol. These findings indicate that alcohol can impair some cognitive aspects of behavioral control before basic motor processes are affected.