Endometriosis is a common condition characterized by proliferation of endometrial tissue outside the uterus, both in the pelvis and in other extra-pelvic sites. The clinical picture of endometriosis is widely heterogeneous. A correct diagnostic work-up of these patients can sometimes be very difficult, since there are a number of gynecological, intestinal and systemic diseases mimicking endometriosis, as well as other conditions that could be associated with or are a consequence of this disorder. Therefore, multidisciplinary care should be encouraged to ensure correct evaluation and improve the management of these patients.