Introduction Care Pathway Management intends to enhance the quality of care by restructuring care services. As recipients of care, patients have relevant experiential knowledge on the provision of care, but they are rarely involved in Care Pathway Management due to various barriers. This study aims to acquire insights into how patients can be meaningfully involved in Care Pathway Management. Methods A case study was conducted to assess the implementation of patient involvement in the co-creation of the care pathways of Soft Tissue Sarcoma and Gastrointestinal Stromal Tumour at Erasmus MC Cancer Institute (the Netherlands), using the Interactive Learning and Action methodology. Within the pathways, seven patients and eight health professionals were involved. To overcome expected and encountered barriers to involving patients, reflection was stimulated on the care pathways and the development process. Qualitative data were collected via interviews, participatory observations and informal conversations. For analysis, a patient involvement evaluation framework and criteria for knowledge co-creation were used. Results Patients indicated specific improvements for current pathways regarding communication, the assistance of a nurse and integrated care. However, the co-creation process encountered several barriers, including limited opportunities to overcome patients’ knowledge gap on medical care services, limited time and uncertainties about responsibilities. Moreover, participatory reflection to enhance the co-creation process was constrained by power imbalances between patients and health professionals and health professionals’ restricted perceptions of their role. Discussion To enhance the meaningful involvement of patients in Care Pathway Management, constraints in joint reflection on the co-creation process must be overcome.