Purpose: In the present study, the authors examined the prospective associations among early language skills, behavioral regulation skills, and 2 aspects of school-age social functioning (adaptability and social skills). Method: The study sample consisted of children with and without a familial risk for dyslexia. The authors analyzed the relations among children's language (at age 2;6 [years;months] and age 5;0), behavioral regulation skills (at age 5;0), and social functioning (at age 8;0) using structural equation modeling. Subgroups of children with respect to language and behavioral regulation skills (at age 5;0) were identified through the use of mixture modeling. Results: Among at-risk children, behavioral regulation skills mediated the association between early language skills and social outcomes. A subgroup of children with poor regulatory and weak language skills scored lower in adaptability, whereas a subgroup having only poor language skills (with normal behavioral regulation) did not differ from a group with age-appropriate skills. Conclusions: The present findings indicate that behavioral regulation skills play an important role in predicting social outcomes among children at risk for language difficulties. Furthermore, it is suggested that various aspects of social functioning may be influenced differently by self-regulation skills and that predictive relationships vary with the degree of language development deficits and accompanying risks.