ABSTRACT Ovarian tissue cryopreservation is an effective method for protecting against infertility as well as preservating endangered animal species. The technique is particularly sought after as a strategy against ovarian failure caused by aggressive chemotherapy in young women with cancer. There are two uses for cryopreserved ovarian tissues after thawing: grafting and culture. Grafting carries the risk of reintroduction of disease. This article describes the status of ovarian cryopreservation in humans and the other animals and also details the successful birth of a pup from preantral follicle oocytes derived from a mouse cryopreserved ovary followed by in vitro growth, in vitro maturation and in vitro fertilization-embryo transfer (IVF-ET).