The current study examined the effects of preschool psychopathology on peer functioning around school entry. Children (N = 211) were assessed at ages 3 and 6. A semi-structured diagnostic interview, the Preschool Age Psychiatric Assessment, was administered to a parent at both time points to assess psychopathology. The peer functioning constructs examined at age 6 included child popularity, socially inappropriate behavior, and conflicted shyness. Simultaneous multiple regressions revealed that age 3 anxiety disorder diagnosis was the only unique diagnostic predictor of age 6 socially inappropriate behavior and conflicted shyness, with age 3 anxiety dimensional scores uniquely predicting all three peer constructs. Age 3 anxiety disorder had direct effects on both socially inappropriate behavior and conflicted shyness, which were not mediated by concurrent anxiety disorder at age 6. Thus, preschool anxiety disorders may have enduring effects on child peer relationships in the early school-age years. Possible explanations and implications are explored.