Endometriosis is defined as the presence of endometrial glandular and stromal tissue outside the uterus that induces a chronic inflammatory reaction. It may be present in up to 22% of asymptomatic women and 30% of women with unexplained subfertility. At present it is estimated that 10%–25% of all patients undergoing IVF are diagnosed with endometriosis and 17%–44% of those also have ovarian endometriomas. in vitro fertilization has become the mainstay of treatment for endometriosis-related subfertility. Although there is some evidence to suggest that medical treatment with GnRH agonist can lead to a reduction in the size of the endometrioma by up to 51% surgical removal of endometriomas remains the most effective approach for patients presenting with subfertility. Despite the lack of a firmly established causal relation between endometriosis and infertility it is clear that treatment of endometriosis can improve fertility in some cases. Expectant management may be a reasonable approach in younger patients with early stage disease and a shorter duration of infertility. Current medical therapy is not efficacious and its use should be discouraged as it may only serve to postpone conception. Laparoscopic surgery appears to be superior to expectant management or medical therapy in minimal–mild endometriosis and may also be of benefit for patients with advanced endometriosis. COH/IUI is a good option in mild and surgically corrected disease. In patients with earlystage endometriosis IVF outcomes are similar to those with unexplained or tubal factor infertility and Gn-RHa treatment combined with IVF may be useful for more advanced disease. In conclusion the standard management of endometriosis in subfertile women before IVF remains controversial owing to the insufficient evidence to suggest superiority of one treatment strategy over another. All the therapeutic options including conservative medical or surgical treatment as well as the advantages and disadvantages should be fully discussed with the patient. Any decision for surgery should be carefully considered and balanced against the risks especially in women with previous adnexal surgery or women with suboptimal ovarian reserve. If the woman opts for surgical treatment she should be appropriately counseled about the potential risks of reduced ovarian function after surgery including the remote possibility of oophorectomy.