This study examined developmental associations between growth in domain-general cognitive processes (working memory and attention control) and growth in domain-specific skills (emergent literacy and numeracy) across the prekindergarten year and their relative contributions to kindergarten reading and math achievement. One hundred sixty-four Head Start children (44% African American or Latino; 57% female) were followed longitudinally. Path analyses revealed that working memory and attention control predicted growth in emergent literacy and numeracy skills during the prekindergarten year and that growth in these domain-general cognitive skills made unique contributions to the prediction of kindergarten math and reading achievement, controlling for growth in domain-specific skills. These findings extend research highlighting the importance of working memory and attention control for academic learning, demonstrating the effects in early childhood, prior to school entry. Implications of these findings for prekindergarten programs are discussed, particularly those designed to reduce the school readiness gaps associated with socioeconomic disadvantage. (Contains 2 tables and 2 figures.)