AbstractBackgroundBrucellosis is an emerging disease that causes a significant impact on productive and reproductive performance in dairy cattle. ThoughBrucellais a pivotal microorganism for dairy cattle, the scenario of brucellosis in Sylhet District is unknown.ObjectivesA cross‐sectional study was carried out to assess the prevalence and determinants associated with brucellosis in dairy cattle of Sylhet District.MethodsA total of 386 sera and data on determinants from 63 dairy herds were collected from 12 sub‐districts using simple random sampling. The sera were tested with Rose BengalBrucellaantigen test,Brucellaabortus plate agglutination test and serum agglutination test to find out the sero‐positivity.ResultsOverall, 17.09% (95% CI: 13.67–21.18) prevalence in cows were calculated. Relatively higher prevalence (56.08%; 95% CI: 42.23–70.32) was recorded in cows having parity ≥4 and were at higher risk (OR = 7.28) than the other cows with parity 0–3. Prevalence was significantly higher in cows with history of abortion 90.63% (95% CI: 75.79–96.76), repeat breeding 79.17% (95% CI: 65.74–88.27) and reproductive abnormalities 48.54% (95% CI: 39.12–58.07). Farm‐level prevalence was high in farms with the previous history of abortion 95.45% (95% CI: 78.20–99.19) and repeat breeding 90.00% (95% CI: 74.38–96.54).ConclusionsThe prevalence was high in Sylhet district, which might be a public health concern. Therefore, this study would represent the baseline information for guiding brucellosis control and prevention.