To women traditionally considered irreversibly sterile due to ovarian failure, oocyte donation and exogenous steroid replacement offers the prospect of achieving a successful pregnancy. Women requiring oocyte donation comprise two main groups: women with primary or secondary ovarian failure, and women with normal menstrual cycles. There will always be an imbalance between supply of and demand for donated oocytes due to ethical considerations. Women of ethnic origin groups must be screened for haemoglobin electrophoresis, sickle cell and Tay-Sachs disease. Adequate and sustained steroid hormone secretion by the corpus luteum of the ovulatory cycle is required for establishing and maintaining pregnancy in humans for the first seven to nine weeks. This chapter discusses oestrogen replacement, progesterone replacement, replacement protocols, oocyte donation in menstrually cyclic recipients, and implantation window. As average life expectancy and quality of life increase, pregnancy from oocyte donation to post-menopausal women becomes more possible.