Introduction: Many inconsistencies have been identified in the translation of evidence-based treatment recommendations for musculoskeletal shoulder pain into healthcare services, with little known about factors influencing decision-making. The objective of this study was to explore the views and experiences of healthcare providers (HCPs) and people living with shoulder pain on treatment decision-making. Methods: Adopting a qualitative design, purposeful sampling was employed to recruit 13 individuals with nonspecific musculoskeletal shoulder pain and 30 HCPs. Data were collected through 1:1 semi-structured interviews and analysed using an approach informed by Constructivist Grounded Theory. To facilitate analysis, two patient and public involvement (PPI) meetings were conducted. Results: Most participants (69%) had shoulder pain of ¿1-year duration. Biomechanical beliefs about shoulder pain predominated and were heavily influential in decision-making for both patients and HCPs. Despite a consensus that therapeutic alliance facilitated decision-making, the extent of collaboration between HCPs and patients in treatment decision-making was rather limited. In addition to condition-specific factors, Individual patient characteristics and resources also influenced treatment decisions. Conclusion: Findings revealed the complexity of the decision-making process for both patients and HCPs, exposing substantial gaps between the reported views and experiences of participants and the principles of client-centred and evidence-based practice. There is a pressing need to enhance the translation of evidence-based knowledge into practice in this clinical area. Patient or Public Contribution: In line with a consultative approach to collaborative data analysis, a subgroup of participants attended two PPI meetings to provide commentary and feedback on preliminary findings.