The comparison of active ingredients across different psychotherapeutic approaches is impeded by the specificity of the theoretical concepts explaining change mechanisms. This study aims to shed light on effective components of the therapeutic process in a trial comparing cognitive therapy (CT) and interpersonal psychotherapy (IPT) in the treatment of social anxiety disorder (SAD). Sixty-two outpatients with SAD were included in the study. Patients and therapists rated common efficacy factors after each session according to the generic model developed by Grawe (2004). Results show significant differences between treatment conditions on several therapist-rated subscales. Therapist ratings revealed a significantly greater focus on behavioral coping strategies in CT as compared with IPT. In addition, CT therapists also reported greater use of resource activation and motivational clarification. No differences were found with regard to problem activation or the therapeutic relationship. Therapeutic outcome was predicted by resource activation and problem activation. Implications of the findings for research and practice are discussed.