Adolescent delinquency is a major concern in Iranian society, influenced by familial and social factors. The present study examined whether self-control mediated the relationship between parental attachment and delinquency among 528 adolescents (63% female) aged 15–17 years recruited from high schools in Tehran. Mediation analysis showed that stronger parental attachment was associated with greater self-control, which in turn predicted lower delinquency. Sobel tests and bootstrapping confirmed self-control as a significant partial mediator for both maternal and paternal attachment. The findings highlight the importance of strengthening parent-child bonds to reduce delinquent behavior among Iranian adolescents.