The present study describes the outcomes of a manualised treatment for generalised anxiety disorder (GAD) in female adolescents that combined traditional cognitive–behavioural therapy (CBT) with an interpersonal skills (IP) component. The CBT component included psychoeducation, somatic management, cognitive restructuring, exposure therapy and problem-solving. The IP component targeted interpersonal avoidance, passive and aggressive interpersonal styles, and co-rumination. Four female adolescents with a principal diagnosis of GAD participated in 10 weekly 1-hour sessions. Adolescent- and parent-report diagnostic interviews and questionnaires were completed at pre-, mid-, and posttreatment, and at 3-months follow-up. Reductions in GAD and depressive symptoms and improvements in interpersonal functioning for all participants on both adolescent- and parent-report measures suggest that the combination of CBT and IP can benefit adolescent girls with GAD.