When considering the typical lesions associated with endometriosis, such as endometriomas, and pelvic adherences involving the tubes, it is very clear how this pathology may impair both natural and assisted reproductive technology (ART) fertility. It may be more difficult for clinicians to recognize that endometriosis can reduce female fertility potential through other mechanisms which may be independent of direct damage to ovarian reserve and tubal function. The most recent clinical studies have shown that endometriosis is associated with increased risk of infertility, independent of the type of endometriosis (ovarian, peritoneal and deep endometriosis). In the IVF setting, the cumulative live birth rate in women with endometriosis has been reported to be significantly lower compared with women without endometriosis. Endometriosis is a complex, multifactorial condition that encompasses not only the presence of endometriotic lesions, but also involves women's sexuality, uterine and ovarian compartment. Endometriosis should always be considered a severe risk factor for infertility and ART failure.