Recently, research has begun to identify cognitive and social-emotional predictors of early academic success. Yet few studies have examined the mechanisms by which children's social-emotional skills are associated with later academic success. The present study examines the associations between preschool emotion knowledge, kindergarten attention skills, and first grade academic competence in a sample of mostly disadvantaged children. Results indicate that attention during kindergarten is a significant mediator of this association, even after accounting for the effects of maternal education, family income, and children's age, sex, and receptive vocabulary skills. The findings provide further support for the implementation of preventive curricula that focus on both social and emotional development as well as attentional development as one strategy for improving future academic success in young children.