While cognitive behavioral therapy (CBT) is considered an evidence based treatment for a range of disorders, individuals differ in their response to treatment. Research investigating the pre-treatment factors that can predict better response to CBT is important because it allows identified factors to be addressed prior to commencing standard CBT protocols, enables modifications to be made to standard CBT protocols, or provides information about suitability for CBT. Pre-treatment attitudes aligned with therapy is a potential predictor of outcome, yet no self-report measure exists. This three-study paper reports on the development of a short self-report measure of attitudes aligned with CBT, named the CBT Suitability Scale (CBT-SUITS). Items were developed rationally based on theoretical models of CBT. Results in community and treatment seeking samples show that the instrument has a clear factor structure and adequate reliability. Results in community samples show that the instrument measures attitudes distinct from symptom severity and predicts CBT credibility. While further research in clinical settings is needed, the CBT-SUITS is an important measure of attitudes aligned with CBT for use in research and clinical practice.