The increasing incidence of malignant diseases that often require gonadotoxic treatment and the tendency to become a parent later in life result in an increased need for fertility preservation.The aim of this position statement is to provide and critically appraise evidence on available options for fertility preservation in both pre-pubertal and post-pubertal men and women.Literature review and consensus of expert opinion.Fertility preservation should be a priority when treating children or adults of reproductive age with agents that may have hazardous effects on the reproductive system. Gonadotoxicity should be kept at a minimum. If gonadotoxic treatment has to be used, methods of fertility preservation should be discussed, as early as possible.