Research Findings: The present study examined the efficacy of a self-regulation intervention with 65 preschool children. Using circle time games, the study examined whether participating in a treatment group significantly improved behavioral self-regulation and early academic outcomes. Half of the children were randomly assigned to participate in 16 playgroups during the winter of the school year. Behavioral aspects of self-regulation and early achievement were assessed in the fall and spring. Although there was no treatment effect in the overall sample, post hoc analyses revealed that participation in the treatment group was significantly related to self-regulation gains in children who started the year with low levels of these skills. Children in the treatment group also demonstrated significant letter-word identification gains compared to children in the control group. Practice or Policy: The findings from this study provide preliminary evidence for the efficacy of the intervention in terms of improving preschoolers' behavioral self-regulation for children low in these skills and improving letter-word identification. Although preliminary, these results have the potential to inform preschool curricula that emphasize behavioral self-regulation as a means of facilitating school readiness. (Contains 4 tables.)