PLAIN ENGLISH SUMMARY: Foundations in Patient-Oriented Research is a course designed and piloted in Canada to help patients, researchers, health care professionals and health system decision-makers gain an introductory understanding of patient-oriented research, the research enterprise, and how to work in a team. The course curriculum was co-developed by a diverse group of people with different lived experiences and relevant expertise. The course is meant to be delivered in a 'co-learning format' with classes comprised of all the above stakeholder groups learning together. The purpose of this study was to explore the experiences of the project leaders, developers, facilitators and patient co-facilitators who were involved in the process of co-developing, piloting and revising the curriculum.Our findings suggest that co-developing a patient-oriented research curriculum increases its quality, uptake and credibility. The co-development process not only resulted in training that benefited the target learners, but it provided valuable learning experiences about patient-oriented research for the project leaders, developers, facilitators and patient co-facilitators. These findings and the resulting recommendations may provide guidance for other learning and development groups wishing to undertake a similar project. ABSTRACT: Background Foundations in Patient-Oriented Research is a course designed and piloted in Canada to build mutually beneficial relationships for conducting patient-oriented research by ensuring that relevant stakeholders - patients, researchers, health care professionals and health system decision-makers - have a common foundational understanding of patient-oriented research, the research enterprise, and team dynamics. The curriculum was co-developed by a group of patients, researchers, patient engagement experts and curriculum development experts and involved consultations with broader groups of the relevant stakeholders mentioned above. It was designed to be delivered in a 'co-learning format' with classes comprised of all stakeholder groups learning together. The purpose of this study was to explore the experiences of individuals involved in the process of co-developing, piloting and revising Foundations in Patient-Oriented Research. Methods An embedded case study was conducted with individuals who were involved in the co-development, pilot and revision of Foundations in Patient-Oriented Research. These individuals took on different roles during the curriculum development process, including project co-lead, developer, facilitator, and patient co-facilitator. The constant comparison method was used to inductively develop themes from the two focus group sessions. Results Discussions from the focus groups revealed the value of co-building the content, co-facilitating the course sessions, and the importance of the co-learning format. The training itself was perceived as valuable and the systematic approach to co-development was perceived as a success. Several barriers were identified, including the amount of resources, time and commitment required to complete the project. There was a notable tension between maintaining the integrity of the content and having the freedom to adapt it to local contexts. Over the course of the project, the project co-leads, developers and facilitators found that their own understanding of patient-oriented research deepened. Conclusions The findings of this study suggest that co-developing a patient-oriented research curriculum increases its quality, uptake and credibility. The co-development process not only resulted in training that benefited the target learners, but also built capacity for patient-oriented research within the project co-leads, developers, facilitators and patient co-facilitators. Our findings and recommendations may provide guidance for other learning and development groups wishing to undertake a similar project.