**Background:** The long-term success of low back pain treatment depends on a multi-faceted therapy process that considers cognition, function, and pain. Sustainable pain management requires self-management and self-management relies on the patients’ quality of adherence. From previous research we know that adherence quality, which is often referred to quantitatively as the level of adherence, can be influenced by various factors such as contacting care providers, level of motivation and supportive environment, self-discipline or time, exercises acceptance, a reminder of exercises and programs, effectiveness of exercises, patients’ beliefs, the therapist-patient relationship, patient involvement, patient attitudes, cultural aspects and language. Furthermore, it is known that physiotherapists’ competencies influence patients’ adherence, too. This is explained by confidence in the need to implement measures to increase the adherence quality in the shortest possible time, e.g., guideline-based practice, communication skills. **Aim:** The aim of this Delphi study is: to find an expert consensus on factors and situations that are influencing the adherence quality of NSLBP patients to physiotherapy (PT). In the long term, this study in combination with the results of previous studies could help to develop an autonomous adherence-focused therapy approach for non-specific back pain patients (NSLBP) patients in PT. **Methods:** This study was approved by the Ethics Committee of the University of Lübeck (registration number: 2023-192). The Delphi method is a consensus method that solicits expert opinion through multiple rounds of interviews. It is characterized by different features: Anonymity, iteration, controlled feedback, and group response (an expression of the degree of consensus within a group). Among the various Delphi methods, the standard Delphi method will be used in this study, which includes approximately 2 rounds of dominantly quantitative items. Data collection by the ratings of the experts in the two rounds of interviews will begin on February 22, 2023 and end on April 01, 2023. The experts practice clinically and/or scientifically in different countries around the world. **Expected results:** The results of the study could show an expert consensus on different factors and situations that influence the adherence quality of NSLBP patients to PT.