Ovarian tumours comprise a great variety of histological types includingfunctional ovarian cysts which do not require surgical treatment. The useof vaginal ultrasound allows the prediction of the histological type of anovarian tumour with high degrees of both sensitivity and specificity.High-resolution imaging of transvaginal ultrasound provides highdiagnostic accuracy for pelvic pathology. There is conflicting dataregarding the diagnostic accuracy of cytologic evaluation of ovariancystic masses.A prospective descriptive cohort study will be conducted at Kasr El-AiniHospital from December 2010 to May 2011. A total of 60 women inreproductive age who have had simple ovarian cysts with benign criteria,which unresolved after taking contraceptive pills for 3 months, wereconsidered for this clinical studyThe objective of this study is to evaluate the accuracy of transvaginalsonography in detecting types of ovarian cysts and compare the resultswith cytological results.In our study results, the accuracy of transvaginal ultrasound comparingwith cytology on diagnosis for functional cysts is 73.9%, for epithelialovarian cyst is 62.7% and for endometrioma is 93.75% (P= 0.0001).