The authors present a case of a 20-year old student from Belgrade, who was admitted to the Institute of Infectious Diseases with fever, muscle and spine pains, strong headacke and malice. During the clinical examination bilateral sacroileitis was found. Serological analyses confirmed brucellosis. Epidemiological data showed that she lived in Kosovo and Metohia in 1997, where she consumed diary products from domestic animals this might be the reason of the acquired infection. With appropriate antibiotic therapy (aminoglycoside, doxicyclin, rifampicin), symptomatic therapy and rehabilitation the disease had favorable outcome; there was no recidive. The authors point out the importance of specific microbiological examinations of patients with fever of unknown origin, especially if the patient has the symptoms that are compatible with brucellosis. In our case it was sacroileitis, as a characteristic complication. As brucellosis is endemic in some parts of our country, there is always a possibility of brucellosis in general medical practice.