Patients’expectancies have long been considered to contribute to treatment outcome. Whereas research has concentrated on different types of expectancies in predicting outcome, it has not examined their interactive contribution, therapist factors, nor the development of expectancies over time. Therefore, the present study aims to investigate the independent as well as the interactive contributions of outcome expectancies (OE) and negative mood regulation expectancies (NMRE) to outcome. One hundred and fourty depressed outpatients in cognitive-behavior psychotherapy completed measures of OE and NMRE at pretreatment and midtreatment, as well as outcome measures at midtreatment and posttreatment. Patients’ OE were assessed using the Patients’ Therapy Expectation and Evaluation Questionnaire (PATHEV; Schulte, 2005), and the short form of the Negative Mood Regulation Scale (NMR; Backenstrass et al., 2010). Outcome was measured using the German version of the Beck Depression Inventory – II (BDI-II; Hautzinger, Keller, & Kühner, 2006), and the Inventory of Depressive Symptomatology - Clinician Rated 30-item version (IDS-C; Rush, Carmody, & Reimitz, 2000). We will perform three-level multiple longitudinal hierarchical analysis, with different assessment time points as the first level, nested in patients (second level), which are nested in therapists (third level), controlling for comorbidities. We expect OE and NMRE to change significantly during therapy, and these changes to be related to outcome, both at midtreatment and posttreatment. We also expect to find a significant interaction between OE and NMRE in predicting outcome, as well as a significant influence of therapists on patients's expectancies. Theoretical and clinical implications of the results will be discussed.