Successful therapeutic work presupposes positive expectations, an active therapeutic stance and assiduous work session-by-session. Therapist expertise may involve the ability to mobilize and work effectively with patient-specific resources and obstacles from the beginning of treatment. In addition to identifying the characteristics and actions of effective therapists, research should also focus on processes emerging within effective therapeutic dyads. Clinical or methodological significance of this article: Our study indicates several factors that seem to characterize therapist expertise and can inform psychotherapy training. Successful therapeutic work presupposes positive expectations, an active therapeutic stance, courage to challenge the patient, and assiduous work session-by-session. Therapist expertise may involve the ability to mobilize and work effectively with patient-specific resources and obstacles from the beginning of treatment. In addition to identifying the characteristics and actions of effective therapists, research should also focus on processes emerging within effective therapeutic dyads.