Women who are diagnosed with cancer during their reproductive lifespan might be confronted with impaired fertility. Nowadays a number of fertility preservation options are available. Decisions about whether and how to protect fertility have to be made in a very short time period, right after cancer diagnosis and before start of treatment. The psychological impact for patients is considerable. This project aims at developing a standardized decision-aid tool to support the decision-making process about fertility preservation in young cancer patients. It is designed as an online decision-aid tool. A web-based tool is perfectly designed for this target group and offers new possibilities providing flexible and individually tailored information.