Endometriosis is an estrogen-dependent disorder mostly occurring in reproductive-age women. Various therapies have been used in an attempt to treat endometriosis, including ovarian suppression therapy, surgical treatment or a combination of these strategies. However, in general, substantial surgery remains the primary treatment option for endometriosis at all stages. Recently, aromatase inhibitors and anti-estrogens have been proposed as novel potential candidates. The rationale for the use of aromatase inhibitors is mostly related to the high aromatase expression in endometriotic cysts and extra-ovarian endometriotic implants. Among anti-estrogens, raloxifene has been investigated in animal models with good results, but in premenopausal women, the compound does not seem to suppress estrogen production.