Transvaginal ultrasound is considered an essential tool for the assessment of pelvic pathology and is often used as a first-line investigation for women with gynaecological symptoms. Initially, only pathologies of the uterus and ovaries could be assessed but with improvements in equipment and particularly the development of specific skills and scanning techniques, it has also become possible to diagnose other gynaecological disorders affecting structures beyond the uterus or ovaries such as deep endometriosis. Despite good test characteristics and an acceptable learning curve, even after more than 10 years, the endometriosis assessment is still considered a specialist assessment. Unless every routine ultrasound examination is extended beyond the uterus and ovaries into the posterior and anterior pelvic compartments to evaluate structural mobility and to look for deep endometriotic nodules, endometriosis will continue to be missed which denies affected women a pre-operative diagnosis and an opportunity of having a single, well-planned procedure in the hands of a well-prepared team. It is therefore time for endometriosis assessment to become an essential part of every routine gynaecological ultrasound examination.