Children's self-regulatory abilities in preschool significantly contribute to social development from preschool to primary school. However, few studies have included both emotionally neutral executive functions and emotion-related facets of preschool self-regulation as predictors of children's social development. This study analyses the role of a broad range of self-regulatory facets (inhibitory control, cognitive flexibility, phonological working memory, delay of gratification, and parent-reported effortful control at 3–5 years) in the development of prosocial behavior and peer relationships at ages 5, 7, and 9, while accounting for factors such as negative affectivity, surgency, receptive vocabulary and previous social development, among others. We used data from a large-scale longitudinal sample of 1898 German children (49.72 % females) and conducted growth curve modeling. Prosocial behavior and peer relationships showed a linear as well as a quadratic growth trend. When analysing the association of various self-regulatory facets to social development, cognitive flexibility, delay of gratification, and parent-reported effortful control were found to be significantly associated with the growth pattern of prosocial behavior, even after including controls and accounting for previous social development. Furthermore, these self-regulatory facets also predicted the development of peer relationships in models that treated emotionally neutral and emotion-related facets of self-regulation separately. Yet, in the overall model, the development of peer relationships was only predicted by parent-reported effortful control and this relation also did not remain significant when accounting for controls and previous social development. Overall, the results suggest a complex relation between self-regulatory facets and social development, requiring further investigation.