History & Objective: Considering different types of ovarian masses and lack of enough information in this regard, the present study was carried out to determine the most common types of ovarian masses in patients admitted at Motazedi Hospital in Kermanshah between 1997 and 2000.Materials & Methods: This study was based on the records of the patients who had been operated at Motazedi Hospital and were diagnosed with ovarian masses. Information about patient's age, type of mass, pathology results, as well as clinical manifestation such as: anorexia, weight-loss, weakness and' fatigue, urinary and gastrointestinal symptoms, vaginal bleeding, constipation and diarrhea, respiratory discomfort, nausea, vomiting, and ultrasonography results were carefully recorded in special forms. The collected data was then analyized by descriptive methods. Results: Analysis of the result showed 55% of 178 cases had non-neoplastic masses and 45% of the masses were diagnosed as neoplastic. It also became clear that the most frequent type of masses among non-neoplastic cases were luteal masses (86.7%), while the most common neoplastic masses were epithelial tumors (67.5%). Most patients in non-neoplastic group (54%) and neoplastic group (45%) were between 20 and 34. But as the age increased, the percentage of neoplastic masses was increased, too. Abdominal pain was the most common symptoms among patients in both non-neoplastic cases (57.3%) and neoplastic cases (66.3%).Discussion: In the light this study it became clear that benign ovarian masses are more frequent than malignant ones. Ofeaurse, of course further studies with respect to factors such as the number of deliveries and impacts of contraceptive pills can give us better understanding.