The aim of this study was to determine the prevalence of brucellosis in sheep, goats, cows and human who are at risk in Diyarbakir region. From ten locations obtained in Diyarbakir, blood samples were collected from sheep, goats and cows belonging to different herds and man who are at risk between 2007 and 2009 years. The blood samples were tested using the Microagglutination (MAT) technique. Seropositivity by using MAT technique on the collected blood samples were positive on 60 (35.2%) of 170 sera taken from the veterinarian, slaughterhouse staff, butchers and growers. Also the positivity rates were 20 (2.9%) of 680, 5 (0.7%) of 725 and 25 (4.3%) of 575 for sera samples taken from cows, sheep and goats, respectively. Consequently, seropositivity is obtained high for animals and individuals who are under risk according to the other regions in Turkey. It is considered that brucellosis can be decreased by informing the individuals who are under risk about the infection of this illness and the works about this subject.