Treatment modalities for numerous oncological and non-oncological conditions result in gonadal insufficiency and infertility. Furthermore, pelvic-abdominal radiation may result in uterine damage resulting in poor reproductive outcomes such as preterm birth, low birth weight, and spontaneous abortion in adult survivors of childhood cancers. In response to the recognition of the impact of cancer treatments on fertility, several fertility preservation techniques have been developed. In prepubertal children, fertility preservation options are usually limited to ovarian cryopreservation because of sexual immaturity, but oocyte freezing can be performed in adolescent children. Two prospective randomized studies showed no benefit of gonadal suppression with GnRH analogs to preserve gonadal function and thus this treatment should not be recommended. For adult survivors of childhood cancer who experienced reproductive failure, third party reproduction techniques are highly successful. Pediatr Blood Cancer 2009;53:267–273. © 2009 Wiley-Liss, Inc.