Considerable evidence has accumulated supporting transactional influences between early childhood behavioral inhibition (BI), parent-child and child-peer relationships, and the development of anxiety disorders in adolescence and adulthood. Drawing from this literature, the Turtle Program was designed to treat children high in BI by intervening at the level of both parents and peers. In this pilot study, we sought to determine whether benefits of participating in the Turtle Program extended to children’s classrooms in the form of increased positive social interactions with peers. Forty inhibited children (42–60 months) and their parent(s) were randomized to either the Turtle Program (n = 18) or a waitlist control group (WLC; n = 22). The Turtle Program involved 8 weeks of concurrent parent and child treatment. Trained research assistants, blind to treatment condition, coded participants’ social interactions with peers during free play at each child’s preschool at the beginning and end of treatment. Teachers unaware of group assignment also provided reports of social behaviors at these time points. (author abstract)