Ovarian damage following cancer therapy is dependent on age at treatment as well as the type of therapeutic exposures. Older age and exposure to higher doses of alkylating agents and higher doses of radiation to the ovary are associated with a greater likelihood of ovarian failure. Acute loss of ovarian function during or shortly following treatment is relatively uncommon in females treated during childhood and adolescence but can be seen following myeloablative, alkylator-based cytoreduction (e.g., busulfan and cyclophosphamide) for stem cell transplant and following direct ovarian radiation with doses >10 Gy. For survivors who retain normal ovarian function after cancer therapy, there is an increased risk of premature menopause later in life. The risk factors associated with an early menopause include exposure to high doses of alkylating agents and abdomino-pelvic radiation.