Objectives: A Randomized Controlled Trial was conducted to evaluate the effectiveness of the Hebrew adaptation of the Program for the Education and Enrichment of Relational Skills (PEERS®), a parent-assisted intervention. Parental sensitivity (PS), measured in conflict and support contexts, was assessed as a predictor of adolescents' intervention-related outcomes.Design: Eighty-two Hebrew-speaking adolescents (9 females), aged 12-17 years, and their parents (62 mothers), were randomly allocated into immediate intervention (II; n = 40) or delayed intervention control (DI; n = 42) groups. Participants were tested at three time-points (Pre-Post-Follow Up for II, Pre-Pre-Post for DI). Outcome measures included behavioral assessments of adolescents' social communication (SC), a social-skills knowledge test, and self, parent, and teacher reported questionnaires. PS was assessed using support and conflict parent-adolescent interactions. Repeated measures ANOVAs were used to assess intervention effectiveness. SEM was used to examine PS pre- and post-intervention as predictors of adolescents' immediate and follow-up outcomes.Results: The II group improved on adolescents' measured SC and social knowledge, on parent-(but not teacher-) reported social skills, and on self-reported empathy. Gains maintained at follow-up. The DI group showed similar gains following their intervention. Adolescents' intervention-related SC gains were negatively predicted by pre-intervention PS, and positively predicted by intervention-related PS changes in the support context. Pre-intervention PS in the conflict context positively predicted adolescent SC at follow-up.Conclusions: The Hebrew-adapted PEERS® is an effective intervention for adolescents with ASD. PS plays an important role in the promotion of SC in adolescents with ASD and should receive clinical attention.