As an addition to the ongoing discussion concerning the magnitude of therapist effects on outcome in psychotherapy, we investigated therapist variability in a large inpatient psychotherapy sample. We included global symptomatic outcome (Global Severity Index of the Symptom Checklist-90 Revised [SCL-90-R]; German version, Franke, 1995) and alliance (Helping Alliance Questionnaire; German version, Bassler, Potratz & Krauthauser, 1995) ratings of 2554 inpatients who were treated by 50 psychotherapists. Multilevel regression analyses (HLM; Raudenbush, Bryk, Cheong, & Congdon, 2004) were used for analyses. Overall, therapists accounted for a much greater variability on alliance (33%) than on outcome (3%). Therapists were differentially effective with regard to their patients' symptom severity at the beginning of treatment, and therapists differed in the degree that a positive alliance was associated with therapeutic outcome. The relatively small therapist effect on outcome is attributed to compensatory mechanisms in the specific context of inpatient therapy.