Recent research has indicated that developmental changes in the personality traits of neuroticism and impulsivity correlate with changes in problem drinking during emerging and young adulthood. However, it remains unclear what potential mechanisms, or mediators, could account for these associations. Drinking motives, particularly drinking to regulate negative affect (drinking to cope) and to get "high" or "drunk" (drinking for enhancement), have been posited to mediate the relationship between personality and drinking problems. Recent work indicates that changes in drinking motives parallel changes in alcohol involvement from adolescence to young adulthood. The present study examined changes in drinking motives (i.e., coping and enhancement) as potential mediators of the relation between changes in personality (impulsivity and neuroticism) with changes in alcohol problems in emerging and young adulthood. Analyses were based on data collected from a cohort of college students (N = 489) at varying risk for alcohol use disorders from ages 18 to 35. Parallel process latent growth modeling indicated that change in coping (but not enhancement) motives specifically mediated the relation between changes in neuroticism and alcohol problems as well as the relation between changes in impulsivity and alcohol problems. Findings suggest that change in coping motives is an important mechanism in the relation between personality change and the "maturing out" of problematic alcohol involvement.