In this pilot study, therapist competence and patient-therapist complementarity measured by the Structural Analysis of Social Behavior system (SASB; Benjamin, 1974) were examined as to their interrelation and their unique, collective, and interactive contributions to patient change in 20 sessions of short-term anxiety-provoking psychotherapy (STAPP; Sifneos, 1979). Patients were 15 highly educated outpatients, mean age 30 years, with mainly anxiety diagnoses. Therapists were in postgraduate manual-guided STAPP training. Results show that competence in an early session did not relate to patient change. In contrast, patient-therapist complementarity ratings predicted patient change both alone and over and above competence. Predictions were strongest for changes in general distress and dysfunctional attitudes and for shorter term change rather than for longer term change.