Aim: Social participation is necessary for the development process of adolescents. It is crucial to gain maturity through the social activities. Social activities lead to an individual who knows their abilities and actualizes their talents. This study aims to examine the mediating role of self-efficacy in the relation of parenting styles with the social participation of adolescents. Materials and Methods: The research has been carried out by the correlational method. The statistical population included all high school students of Arak. The sample of the study consisted of 510 students (255 boys and 255 girls) who were selected through the cluster sampling method. The instruments of gathering the data were Bumrind's parenting styles questionnaire, Sherer's general self-efficacy scale, and Branigan's eagerness to participate in social activities. Data analysis was performed using the structural equation method with Smart Partial Least Square software(SmartPLS GmbH, New York, USA). Results: The results showed that the direct effect of the permissive parenting style on social participation and its indirect effect through self-efficacy mediation (P <0.05), the direct effect of authoritarian parenting style on social participation, and its indirect effect through self-efficacy mediation (P <0.05), and finally, the direct effect of the authoritative parenting style on social participation and its indirect effect through self-efficacy mediation on social participation was statistically significant (P <0.05). Conclusions: According to the findings, it concluded that self-efficacy plays a significant mediating role in the relationship between parenting styles and the social participation of adolescents. Application and theoretical implications are discussed.