Introduction: Blended Cognitive Behaviour Therapy (bCBT) uses a combination of face-to-face sessions and online material, such as self-help modules, and can be used in the treatment of depression. The blended format has the potential of integrating internet-based components into treatment without completely removing the traditional face-to-face setting. This way of delivery can lower the threshold when it comes to using digital components in CBT. The role of therapeutic alliance in this format is yet to be explored, specifically the role of therapist rated alliance, as most studies only include patient rated measurements of alliance. Methods: Working alliance and depression ratings from 73 participants in a study on bCBT for depression (part of the E-COMPARED project) was analysed using growth curve models. Results: High ratings for both patient-and therapist rated working alliance were found. Therapist rated alliance predicted a positive change (decreased PHQ-9 scores) in depression during treatment. Discussion: Ratings of therapeutic alliance was similar to what have been seen in face-to-face and internet-based treatment. Patient rated alliance could not predict change rate in depression, which is a common finding in ICBT-studies. However, therapist rated alliance had a significant correlation with change rate and predicted a decrease in depression during treatment. These results sheds more light on the concept and role of therapeutic alliance in internet-based and blended treatments.