SUMMARY The prevalence of brucella infection among different species of farm animals in Assiut Governorate was estimated by using Rose Bengal plate test (RBPT), Buffered acidified plate antigen test (BAPAT), Tube agglutination test (TAT), Rivanol test (Riv.T.) and Enzyme linked immunosobent assay (ELISA). A total number of 197 cattle blood samples were examined serologically. Brucellosis incidence allover Assiut Governorate was 3.6 %. On the other hand, slaughter houses revealed the highest infection rate (7.1 %) followed by private flocks (1.6 %). While governmental farms did not record any infection rates in this study. A significant correlation between sexually mature animals and the rate of infection was observed. The incidence of brucellosis among cattle was varied according to sex from 0.00 % in males to 6 % in females. Seroprevalence of brucella infection among 129 sheep blood samples was 11.6 % all over the governorate. A highest attack rate (50 %) was observed among the age group 2.3- 2.6 years. The incidence of brucella infection was 12.2 % in ewes while no positive cases were recorded in rams. The serological examination of 32 buffaloes' sera did not detect any positive re- actors. The role of these animals in transmitting infection to humans was discussed. The public health hazard from detecting brucella antibodies in 7.3 % of the composite milk from 41 dairy cows was also clarified.