The majority of children from lower income families enter elementary school well behind their peers in reading, math, and general knowledge. Poor academic achievement in the early grades is associated with a range of social problems such as failure to complete high school, increased risk of unintended pregnancy, increased criminal activity, and insufficient wages. There has been a steady increase in the number of publicly funded preschool programs designed to help children from a range of disadvantaged backgrounds develop school readiness skills. Social work has been minimally involved in preschool programs, even as policymaker interest and public support for these programs have grown. This article reviews the outcomes research on preschool intervention programs and discusses the implications of this research for social work policy advocates and practitioners.