Social anxiety is inconsistently associated with alcohol use variables. To elucidate factors that contribute to the relationship between social anxiety and problematic alcohol use, the present study investigated drinking motives and drinking situations in an undergraduate sample (N = 293). Social anxiety was significantly correlated with endorsement of enhancement drinking motives (i.e., drinking to enhance positive experiences or emotions) but not social or coping motives. Social anxiety was also correlated with endorsement of drinking in the following high-risk situations: unpleasant emotions, conflict with others, social pressure, and testing personal control. Importantly, enhancement motives and each of these drinking situations mediated the relationship between social anxiety and alcohol-related problems. Findings suggest that alcohol use to enhance positive affect or in response to these specific situations may account for the risk for alcohol-related problems among those with social anxiety. (Contains 2 tables.)