The primary goal of this study was to examine a complex theoretical model linking shyness, fear regulation, parental emotion socialization, and indices of social adjustment in preschoolers. Participants were N = 262 preschool children (ages 2-5 years; M = 3.23, SD = .51). Parents rated children’s shyness and fear regulation strategies in the Fall (Time 1) and early childhood educators assessed indices of children’s social adjustment in the Spring (Time 2). Among the results, shyness was negatively associated with fear regulation and positively associated with socially withdrawn behaviours at preschool. A significant age moderated-mediation effect was also found, whereby fear regulation mediated the negative association between shyness and prosocial behaviour among older preschoolers, but not among younger preschoolers. Overall, the results provide some initial evidence to suggest that fear regulation may play a unique role in older preschoolers’ social adjustment.