The purpose of this study is to examine the influence of peer play behaviors on rates of growth in academic readiness in a sample of multiethnic, low-income children enrolled in Miami-Dade County Head Start. The specific intent is to: (1) identify profiles of Head Start children based on their peer play behaviors; and (2) examine whether these profiles of children are differentiated by growth in multiple school-readiness domains. The study will employ a child-centered approach by utilizing peer play as a context to identify subgroups of children who display specific patterns of behavior, and will examine how the academic trajectories of math, literacy, and science of these children differ during one year of enrollment in Head Start. It is expected that results of the study will contribute to the understanding of the influence of peer play on academic readiness. Results could also contribute to the development of specific interventions or curriculum strategies within Head Start classrooms to support socially-meditated learning experiences.