Serological survey of Brucella antibodies in cattle herds was carried out in all the five agricultural zones of Yobe state, Nigeria. Four hundred (400) cattle serum samples from different herds located in all the agricultural zones of the state were screened by Microtitre Serum Agglutination Test (MSAT). One hundred structured questionnaires were also administered to pastoralist herdsmen in the state. Out of the four hundred (400) sera screened, 136(34.0%) was seropositive. Of the 136 seropositive cattle, 32(8.0%) were male while 104(26.0%) were female cattle. There was no significant statistical difference (P>0.05) in the sero-prevalent rates between the male and female cattle screened. The highest specific sero-prevalence of 14.0% was obtained in the age band of 5–6.5years, while the least (1.5%) was obtained in the age band 1–2.5 years. Geidam zone with 12.0% specific sero-prevalence was the highest among all the zones of the state while Damaturu zone recorded the least (3.5%). The white Fulani breed recorded the highest specific sero-prevalence of 15.0% followed by Wadara, 9.5%, Red Bororo 5.5% and Adamawa Gudali 3.5 %. There was no significant statistical difference in the age, breeds and agricultural zones of the state (P>0.05). Also there was no significant statistical association between the sex of the cattle and Brucella infection. The study concluded that brucellosis was still endemic in the herds of cattle in Yobe State. The sero-prevalence was higher among females than males and in the adults than in the young cattle studied. Key words: Brucellosis, cattle, sero-prevalence, Nigeria, Yobe.