Endometriosis-associated infertility is a common indication for in vitro fertilisation (IVF) treatment. There is great controversy regarding the outcome of IVF in such patients. Possibly inferior results compared with other indications for IVF are likely based on reduced oocyte and embryo quality and not adverse endometrial receptivity. Such knowledge is based on IVF crossover studies with donor oocytes and patient’s own oocytes to women with and without endometriosis. Embryos that are frozen and later thawed for transfer to the uterus are selected among the best embryos in a fresh cycle. Transfer of such embryos is as successful in endometriosis as in other causes of infertility whatever endometrial preparation is used. Thus, long-term suppression of endometriosis with GnRH agonists in frozen embryo transfer is unnecessary and may possibly be harmful due to induction of endometritis.