Abstract. The present study examined whether personality traits and drinking motives interact to predict binge drinking and alcohol-related problems in a cross-cultural sample of college students. Participants were undergraduate drinkers ( N = 904; 66% female) from universities in Portugal ( N = 391) and the US ( N = 513). Participants completed measures assessing neuroticism, extraversion, conscientiousness, drinking motives, frequency of binge drinking, and the number of alcohol-related problems. A significant Country × Neuroticism × Conformity interaction was explained by differences between US and Portuguese samples. The effect of this interaction on alcohol- related problems was mediated by binge drinking. Findings suggest similarities and differences across cultures in the manner in which personality and drinking motives are associated with alcohol outcomes. Across cultures, neuroticism, extraversion, conscientiousness, and drinking motives are key factors to consider in the assessment, prevention, and treatment of alcohol use among college students.