Brucellosis is a widespread infectious disease of livestock and wild life with serious economic and public health impact. Bovine brucellosis causes diminution of much needed human food (milk and meat). Besides, being transmitted to man, it is one of the most important causes of abortion, stillbirth and infertility in cattle. The objectives of this study were, to investigate the current epidemiological picture of brucellosis in cattle in intensive and extensive management systems, identify and describe some of the associated intrinsic and extrinsic risk factors and to see the zoonotic importance of the disease.rnThe study was conducted from September 2003 to April 2004, in Sidama Zone (Southern Nations Nationalities Peoples Regional state). In the study area, six out of ten Woredas were considered for the investigation. Breeding cattle (n=2438) above six months of age were drawn in from both management systems with no history of vaccination. To this effect, a total of 811 Frisian and their crosses from intensive and 1627 indigenous zebu from extensive management system were considered. Furthermore 38 individuals thought to be at risk due to their occupational nature, with particular emphasis given to Veterinarians, Animal health Assistants, Animal Health Technicians, Artificial Insemination Technicians and Meat Inspectors were made part of the study.rnSerum samples collected from both animals and humans were screened using Rose Bengal Plate Test (RBPT). Positive reactors were further subjected to Complement Fixation Test to maximize specifity and positive predictive value.rnIn this study, an over all prevalence of 2.46% in intensive and 1.66% in extensive management systems has been established. Among the risk factors investigated (Age, sex, herd size and management), only age was found to be associated with the infection (P