Brucellosis is an important occupational disease, mainly among veterinarians, because of their frequent contact with sick animals, contaminated secretions and live attenuated anti-Brucella vaccines. This study aimed to determine the prevalence of accidental exposure to S19 and RB51 vaccine strains and occupational brucellosis among veterinarians registered to administer vaccinations in Minas Gerais, Brazil, as well as to identify the risk factors associated with accidental exposure to anti-Brucella abortus vaccines. Data were collected through an online questionnaire. Three hundred and twenty-nine veterinarians were included in the analyses using stratified random sampling. A multivariate logistic regression analysis was used to evaluate the predictors of accidental exposure to S19 and RB51 strains. Nearly one-third of the veterinarians registered to administer bovine brucellosis vaccination in Minas Gerais, 32.83% (108/329) [95% confidence interval (CI): 27.78 to 38.19%], reported having been accidentally exposed to S19 or RB51 vaccine strains. The exposure factors associated with this outcome included a score of personnel protective equipment (PPE) use during work [odds ratio (OR), 0.94; 95% CI: 0.89 to 0.98] and a score of knowledge about brucellosis symptoms, classified as poor (base category), intermediate (OR, 0.26; 95% CI: 0.07 to 0.87), or good (OR, 0.22; 95% CI: 0.07 a 0.62). In addition, 4.56% (15/329) (95% CI: 2.57 to 7.41%) of veterinarians reported that they had brucellosis, of which 46.67% (7/15) considered that the disease was due to accidental exposure to anti-B. abortus live-attenuated vaccine. The prevalence of accidental exposure to B. abortus vaccine strains among veterinarians from Minas Gerais enrolled in the control of bovine brucellosis was high. The reduced knowledge about human brucellosis symptoms and lack of appropriate PPE use were risk factors from unintentional contact with S19 and RB51 vaccine strains.This article is protected by copyright. All rights reserved.