The role that parents' involvement may play in improving their child's social anxiety is still under debate. This paper aimed to investigate whether training parents with high expressed emotion (EE) could improve outcomes for adolescent social anxiety intervention. Fifty-two socially anxious adolescents (aged 13-18 years), whose parents exhibited high levels of expressed emotion, were assigned to either (a) a school-based intervention with an added parent training component, or (b) a school-based program focused solely on intervening with the adolescent (no parental involvement). Post-treatment and 12-month follow-up findings showed that school-based intervention with parent training was superior to the adolescent-specific program, yielding significant reductions in diagnosis remission, social and depressive symptomatology, particularly when the EE status of parents changed. Overall, the findings suggest that high-EE parents of children with social anxiety need to be involved in their child's therapy.