Background: The prevalence and risk factors for endometriosis may differ according to diagnosis methodologies,such as study populations and diagnostic accuracy. We examined risk profiles in imaging-diagnosed endometriosiswith and without surgical confirmation in a large population of Japanese women, as well as the differences in riskprofiles of endometriosis based on history of infertility.Methods: Questionnaires that included items on sites of endometriosis determined by imaging techniques andsurgical procedure were mailed to 1025 women who self-reported endometriosis in a baseline survey of the JapanNurses’ Health Study (n = 15019).Results: Two hundred and ten women had surgically confirmed endometriosis (Group A), 120 had imaging-diagnosed endometriosis without a surgical procedure (Group B), and 264 had adenomyosis (Group C). A shortmenstrual cycle at 18–22 years of age and cigarette smoking at 30 years of age were associated with significantlyincreased risk of endometriosis (Group A plus Group B), while older age was associated with risk of adenomyosis(Group C). In women with a history of infertility, a short menstrual cycle was associated with a significantlyincreased risk of endometriosis in both Group A and Group B, but risk profiles of endometriosis were differentbetween Group A and Group B in women without a history of infertility.Conclusions: Women with surgically confirmed endometriosis and those with imaging-diagnosed endometriosiswithout surgery have basically common risk profiles, but these risk profiles are different from those withadenomyosis. The presence of a history of infertility should be taken into consideration for evaluation of risk profiles.Key words: endometriosis; risk factors; validation