This study was conducted from September 2000 to September 2004 on 8 cases of inguinal canal endometriosis. All the patients presented an inguinocrural tumefaction of variable size. In 3 cases (symptomatic endometriosis), the patient's medical history yielded a preoperative diagnosis. In the other 5 cases (asymptomatic endometriosis) we obtained an incidental intraoperative diagnosis. In 2 of these, concomitant frank inguinocrural disease further hampered the preoperative diagnosis, while in the other 3 cases we were oriented towards an inguinal adeno-lymphatic disease. We found no signs of neoplastic transformation in our case series. The histological examination confirmed the diagnosis of endometriosis in all 8 cases, without any atypical cellular signs. From an analysis of the literature we deduced that the worldwide incidence of endometriosis is about 10% of the female population, though it is known that in the vast majority of cases there are few or no symptoms. Even today, despite the routine use of advanced diagnostic and surgical procedures, endometriosis foci are very often identified only incidentally owing to the greater incidence of asymptomatic or paucisymptomatic forms. The aim of our study is to stress the difficulty in diagnosing asymptomatic endometriosis and, above all, to suggest that, in the presence of a concomitant hernial pathology in a woman of child-bearing age, the diagnostic hypothesis of endometriosis should never be disregarded.