Bovine brucellosis is an endemic zoonosis prevalent in Brazil. Cervical bursitis is a brucellosis suggestive lesion found in bovine carcasses. This work aimed to study risk factors for brucellosis seropositivity and for Brucella abortus isolation in bovine carcasses with cervical bursitis from the states of Mato Grosso, Pará and Tocantins – Brazil, through Bayesian Logistic Regression Models (BLRM). Results of the diagnostic tests were the dependent variable in three distinct BLRM (model 1 serum aglutination test with 2-mercaptoethanol SAT/2ME, model 2 – rose Bengal RB and model 3 – isolation and identification Bac). Origin of the samples, sex and age of the animals were the explanatory variables. Females were 18.54 (95%CrI 4.727 – 85.98), 16.03 (95%CrI 4.198 – 71.57) and 5.796 (95%CrI 1.551 – 32.13) times more likely to be seropositive for brucellosis or had Brucella abortus isolated from the lesions than males, in models 1, 2 and 3 respectively. There was no risk associated with the age of the animals. The origin of the animals was a factor that reduced the risk for brucellosis in two models. The information provided in this study can support risk-based sampling for brucellosis vigilance and risk analysis.