Introduction Young adulthood is a period of rapid occupational role development. While the impact of a cancer diagnosis at this time is likely to be substantial, little research has addressed this topic. The aims of this study were to gain insights into the impact of cancer on occupational roles throughout the cancer disease trajectory, from diagnosis to the palliative stage, for one young person. Methods A longitudinal case study design was used. Five semi‐structured interviews, layered with photo elicitation, were conducted over 3 years. Qualitative data were analysed thematically. Results Three themes emerged: the adjusted plan, establishing rules, and damage control and self‐preservation. Challenges impacting participation in, and meaning of, and the occupational roles themselves shifted over time. Conclusion Findings provide knowledge of occupational adaptation, and the reconstruction of occupational role identity and participation, of the young adult living with cancer along the disease trajectory.