The aim of this study was to determine prevelance of brucellosis and to estimate sociodemographic factors associated with brucellosis in Sivrihisar district center and its villages. Study period was from August-September 2004. Participants were occured 3707 persons (59.8% women) and the living in 14 parishes and 33 villages dependent to Sivrihisar district center. Mean age was 47.24 ± 16.88. A questionnaire was to application with face to face method and it was to interrogation sociodemographic caracteristic, spesific epidemiological caracteristic of brucellosis and its symptoms. After than, 2-3 ml venous blood samples were collected by each participants and Rose-Bengal test was studied. Chi square and McNemar tests were used for statistical analysis. General symptoms and physical examination signs' sensitivity and specificity were calculated by Rose- Bengal test results. Prevelance of Rose-Bengal test (+) was 11.5%. By Rose-Bengal test results, seroprevelance rate was found high in farmers, living in villages, housewifes, working on stockbreeding in home or farm and consumption fresh cheese and cream. It was determined high sensitivity and low specificity for back pain-muscle pain and articulation pain- articulation swelling. But low sensitivity for other symptoms and physical examination were indicated that this symptoms and physical examination were nonspesific in brusellosis. In result, brucellosis was found commonly in Sivrihisar district center and its villages. These results suggest that planning public educational programme about transmission routes and prevention of brucellosis, and vaccination of animals and to provided early diagnosis and treatment of patients with brucellosis.