Oocyte donation offers the prospect of achieving a successful pregnancy to a group of patients traditionally considered to be irreversibly sterile. In patients with ovarian failure; it is possible to create an endometrial milieu that is receptive to embryonic implantation by giving exogenous steroid replacement. A high fertility potential can be achieved with a low miscarriage rate in oocyte recipients irrespective of the patient's age. This reflects the improved biological performance of oocytes obtained from young donors. In oocyte recipients, it is now feasible to dissociate the stages of embryonic development and endometrial maturation. Hence, oocyte donation can provide insights into as yet unresolved questions such as the duration of the ‘ implantation window’ in humans. Oocyte donation will undoubtedly complement basic IVF in trying to elucidate the biological interactions between the conceptus, endometrium and steroid environment in human reproduction.