The current study was applied from January to December 2019 to determine and identify the prevalence rateof bovine brucellosis and its correlated risk factors in dairy herds in Nile delta, Egypt. The study populations comprised of 300 dairy farms which including 4000 dairy cattle. Estimated results showed that, the prevalence of brucellosis in dairy cattle was 6.05 % that depended on the result of CFT. The univariate statistical analysis revealed that positive cases of brucellosis was clearly higher in cattle housed under the intensive management system, and animals in the extensive management system had lower prevalence (P <0.001). Moreover, there was a statistically correlation between brucellosis and the age of animals (P < 0.01) but correlation was weak with the number of labor (P > 0.05). Significant increasing of positive cases was parallel with the increasing of the size of herd (P < 0.05). Sero-positivity to brucellosis was significantly correlated with history of abortions or stillbirths. The results estimated that brucellosis is endemic and widely distributed disease in Nile delta, Egypt.