IMPORTANCE: Atraumatic shoulder pain significantly burdens society and the individual. There is a growing need for involving patients and other stakeholders in setting the research agenda. OBJECTIVE: To use the voices of people with atraumatic shoulder pain, healthcare practitioners, and their relatives to establish research questions. DESIGN, SETTING, AND PARTICIPANTS: This priority-setting study followed a modified approach originally formulated by the James Lind Alliance (JLA). The process consisted of six phases (initiation, consultation, collation, prioritization, validation, and reporting) and included two e-surveys and two separate virtual workshops. Data collection started on June 2021 until June 2023. We included people with atraumatic shoulder pain, relatives, healthcare practitioners managing shoulder pain, and researchers conducting research within the field. EXPOSURES: The first e-survey included basic demographic questions and the possibility to submit at least one and a maximum of five potential research questions. Based on a thematic analysis, questions were arranged into themes and related questions. In the second e-survey, participants were asked to prioritize the questions. Finally, two priority-setting partnership workshops were used to formulate a top-10 list. MAIN OUTCOMES AND MEASURES: A top-25 and top-10 list of research questions related to atraumatic shoulder pain. RESULTS: Initially, 297 participants submitted 1080 potential research questions. In the second e-survey, 290 participants prioritized these questions resulting in a compilation of the top 25. Based on discussions from the workshops with 21 participants, a top 10 list was created. CONCLUSIONS AND RELEVANCE: In the final top 10 list, the three research questions with the highest ranking concerned 1) translating the best available knowledge into clinical practice, 2) preventing shoulder pain, and 3) identifying who benefits from surgery. These questions inform future research funding and projects relating to atraumatic shoulder pain.