Endometriosis is a gynecological disease affecting about 10% of the female population. The multifactorial hormonal, inflammatory, genetic, mental and behavior pathogenesis can result in chronic pelvic pain, blooding disorders and infertility causing disruption of quality of life. Correct diagnosis of the extension and topography is substantial in defining the adequate therapeutic strategy. In an increasing proportion of the cases, endometriosis is being managed medically and para-medically; diagnostic or therapeutic surgery can often be avoided or delayed. Transvaginal sonography is considered being the first-line imaging method in the diagnosis of pelvic endometriosis. The paradigm shift from the belief that endometriosis only affects women of reproductive age has drawn attention to endometriosis in both premenarchal and postmenopausal patients. This review resumes the actually recommended ultrasound signs in the case of patients in menstrual age. Specific diagnostic approaches in adolescent and menopausal patients are highlighted.