Aim: Endometriosis in adolescent girls has severe morbidity and late sequelae.  Our aim was to find out the role of a noninvasive tool like Benjamin Sign for its diagnosis.

Method: Adolescent and young girl 10–24 years of age with complaint of pelvic pain, dysmenorrhea, menstrual irregularity, infertility attending the female Out Patient Department of S.S.H., B.H.U. from Sept. 2008 to June 2010 were selected. Basal Body Temperature charting was done from D₂₂ to the end of the menstruation. Laparoscopy was done in suspected cases.

Results:Total 52 patients were evaluated; laparoscopy was done in 35 cases on the basis of Benjamin sign positivity,strong clinical suspicion & ultrasound diagnosis.Benjamin sign was positive in 93.3% cases of endometriosis (positive predictive value).Sensitivity was 96.55%. Specificity was 66.66%

Conclusion:   Benjamin sign as a non invasive cost effective tool which can be evaluated for making of diagnosis of endometriosis