For patients who are planning to have chemotherapy, radiotherapy or to undergo bilateral oophorectomy, loss of ovarian function will result in premature ovarian menopause and loss of fertility. For these women, although there is no successful method for the cryopreservation of human oocytes, ovarian tissue cryobanking is proposed with a view to its autotransplantation at a later date or the isolation and in-vitro maturation of oocytes. Embryo preservation is indeed not an option for single women and even for married women because delaying treatment for at least 2 months of in-vitro fertilization cycles is inappropriate and life-threatening. Following the success of animal experiments, there have been reports of ovarian cryopreservation for women having to receive chemotherapy and/or radiotherapy. We present four case reports of ovarian tissue cryobanking and review the consequences of chemotherapy and radiotherapy on gonadal function, as well as the indications for freezing ovarian tissue.