The goal of this study was to examine the role of attention regulation as a mediator between parent-child relationships and peer social skills. Using the National Institute of Child Health and Human Development (NICHD) Study of Early Child Care and Youth Development data set, mother-child and father-child relationships measured at 54 months and grade 1 predicted peer social skills at first and third grades. Attentional control processes, especially ability to sustain attention and ratings of attention problems, served as mediators between parent-child relationships and peer outcomes. The implications of these processes for theories of family-peer relationships are noted.