The present research sought to investigate the relationship between mothers' attachment style and their teenagers’ social and academic adjustment. This study had a correlational-descriptive design. The statistical population of the study was comprised of all adolescent girls and boys aged 14 to 18 years in Tabriz and their mothers in 2021. Convenience sampling method was used and 366 students (245 girls & 121 boys) were selected. The research instruments included Adult Attachment Inventory (AAI, Besharat, 2005) and Adjustment Inventory for School Students (AISS, Sinha and Singh, 1998). Data were analyzed using Pearson correlation coefficient and simultaneous multiple regression. Results demonstrated that: 1) There was a significant relationship between mothers' secure attachment style and adolescents’ social adjustment (p≤0.05). 2) There was a significant relationship between the insecure/avoidant attachment style of mothers and adolescents’ social adjustment (p≤0.05). 3) There was a significant relationship between the insecure/avoidant attachment style of mothers and adolescents’ academic adjustment (p≤0.01). 4). There was a significant relationship between the insecure/ambivalent attachment style of mothers and adolescents’ academic adjustment (p≤0.01). According to these results, it can be concluded that mothers who have a secure attachment style, their children have higher social cognition as well as higher social adjustment, while mothers who have insecure attachment style, their children have lower social and academic adjustment. The type of attachment style of mothers can play an important role in the attachment style of children as well as their behavioral, emotional and social status in later years.