Abstract Background/Aims Worldwide, many people who would benefit from osteoporosis treatment are not offered or receiving them, resulting in an osteoporosis care gap. Adherence with bisphosphonates is particularly low. This study aimed to identify stakeholder research priorities relating to bisphosphonate regimens for the treatment of osteoporosis. Methods A three-step approach based on the James Lind Alliance methodology for identification and prioritisation of research questions was used. Research uncertainties were gathered (Step 1) from recent published international clinical guidelines and a large programme of related research studies about bisphosphonate regimens: the ‘Bisphosphonate aLternAtive regimenS for the prevenTion of Osteoporotic Fragility Fractures’ (Blast Off) study, which consisted of six discrete individual research studies conducted between May 2019 and February 2022, relating to the experience, effectiveness and cost-effectiveness of different bisphosphonate regimens. Clinical and public stakeholders refined the list of uncertainties into research questions (step 2) and then prioritised the questions using a modified nominal group technique (step 3) in two, day-long online workshops. Results In total, 34 draft uncertainties were finalised into 33 research questions by stakeholders. Twenty nine stakeholders were involved in refining uncertainties and prioritisation, including 16 public contributors, 2 Allied Health Professionals, 3 GPs and 8 Consultants. The top 10 questions are shown in Table 1. Conclusion This study reports, for the first time, topics of importance to stakeholders in the research of bisphosphonate osteoporosis treatment regimens. The priorities address how to better implement guidelines to address the care gap, understanding patient factors influencing treatment selection and effectiveness, and how to optimise long-term care. These findings have implications for research into implementation to address the care gap and education of healthcare professionals in the treatment of osteoporosis. Disclosure Z. Paskins: None. A. Moult: None. N. Corp: None. A. Bastounis: None. S. Davis: Grants/research support; Grant from Roche Diagnostics to her employing insitution to fund research into the cost-effectiveness of using a biomarker to monitor response to treatment with antifracture medication. M. Narayanasamy: None. J. Griffin: None. N. Gittoes: None. J. Leonardi-Bee: None. T. Langley: None. S. Bishop: None. O. Sahota: None.