BACKGROUND Several studies suggest that cognitive deficits seen in late stages of alcoholism are related to executive function. However, little is known about the acute effects of alcohol on cognitive executive functions. OBJECTIVE The present investigation examined the acute effects of a moderate alcohol dose on tests of planning and spatial working memory as well as on tests of spatial and pattern recognition. The relationship between the acute alcohol effects on performance in these tasks and extreme drinking patterns were also studied. METHODS Alcohol (0.8 g/kg) or placebo was administered to 95 social drinkers. In the planning task, alcohol decreased the number of solutions with the minimum moves. Alcohol also decreased the thinking time before initiating a response, while it increased the subsequent thinking time in the same task. Under alcohol, participants recognised fewer items in the spatial recognition task; however no effect of alcohol was found in a spatial working memory task and in a pattern recognition task. Among the participants with moderate to heavy use of alcohol, those who were 'bingers' performed worse in the spatial working memory and in the pattern recognition task than 'non-bingers'; no interaction between treatment and drinking pattern was found. CONCLUSIONS These data suggest that alcohol given acutely impairs executive-type cognitive functions and that binge drinking may be associated with impaired cognitive function in a working memory and a pattern recognition task.