As cancer survival rates continue to improve, many young adults and children will face infertility after successful treatment of their malignant diseases. Fertility is now recognized as a critical component of quality-of-life for cancer survivors and fertility preservation is an emerging discipline that addresses the need for improving cancer survivors' options to have children later in life. Fertility preservation by established methods is often possible in adult female and male cancer patients before starting their gonadotoxic treatments. In prepubertal children, options are still experimental and most challenging. Embryos, oocytes, sperm, or gonadal tissue (ovarian and testicular) can be cryopreserved and stored at subzero temperatures until the time when the patients are disease-free and wish to start a family. As fertility preservation choices include both established and experimental techniques, a highly individualized approach is required in the management of those patients looking for fertility preservation options.