Women diagnosed with cancer have to make time-pressured decisions regarding fertility preservation with specialist fertility services whilst planning their cancer treatment with oncology services. Oncologists identify a need for resources enabling them to support women's fertility preservation decisions more effectively; and women report wanting more specialist information to make these choices across service pathways. This research will develop a new evidence-based patient decision aid (PDA) to address this unmet need and evaluate its acceptability to women and services when integrated into usual cancer care pathways at the point of cancer diagnosis and treatment planning.