This study developed a model of impaired inhibitory control in humans to test the efficacy of treatments for this deficit. Male social drinkers (N = 35) practiced a "go-stop" task that measured response inhibition. They then were assigned to 1 of 5 groups (n = 7) that performed the task under a different treatment. The model of impaired inhibitory control was provided by administering 0.62 g/kg alcohol to 1 group (A), whose response inhibition was compared with a placebo group (P). The other 3 groups received 0.62 g/kg alcohol plus a treatment designed to ameliorate alcohol impairment of inhibitory control: behavioral reinforcement (B), or 4.4 mg/kg caffeine (C), or a combination of both (B + C). Alcohol impaired inhibitory control, and all 3 treatments (B, C, and B + C) counteracted the impairment. The findings indicate that alcohol impairment of response inhibition may provide a useful human model to test conditions that may ameliorate or exacerbate deficits in behavioral control induced by drugs or other factors.