OBJECTIVE: To assess the accuracy of new transvaginal ultrasound-scan-based markers and to compare them to conventional ultrasound methods used in the detection of common pelvic pathology in women with chronic pelvic pain (CPP). DESIGN: A prospective observational study. SETTING: Teaching hospital. POPULATION: A total of 120 consecutive women with CPP undergoing transvaginal ultrasonography before either diagnostic or operative laparoscopy. METHODS: Anatomical abnormalities, e.g. endometrioma or hydrosalpinx (hard markers), were documented. The woman was then assessed for the presence or absence of 'soft markers' (reduced ovarian mobility and site-specific pelvic tenderness). MAIN OUTCOME MEASURE: Presence or absence of pelvic pathology noted during laparoscopy. RESULTS: Seventy women had pelvic pathology, of whom 51 had endometriosis alone, 7 both endometriosis and pelvic adhesions, 6 pelvic adhesions, 1 hydrosalpinx with endometriosis and 5 hydrosalpinx and pelvic adhesions. The likelihood ratio for the hard markers was infinity (specificity was 100%), for the soft makers 1.9 (95% CI 1.2-3.1) and for a 'normal' ultrasound 0.18 (0.09-0.34). The pre-test probability of pelvic disease in our population of women with CPP was 58%, and this probability of disease was raised to 100% with the presence of hard markers and to 73% with the presence of soft markers. The pre-test probability of 58% fell to 20% when ultrasound finding was found to be normal. CONCLUSION: This new approach improves the detection and exclusion of significant pathology in women with CPP and may lead to a reduction in the number of unnecessary laparoscopies carried out on women with CPP.