This study aimed to evaluate the psychometric properties of the Brazilian version of the Burnout Assessment Tool (BAT-Brazil), a new measure of burnout. To assess validity evidence, the BAT-23 was administered to a sample of 2,223 Brazilian participants, while the BAT-12 was completed by 4,022 participants. Both samples included workers from the five regions of the country. The factorial validity and the reliability of the BAT-Brazil were examined through confirmatory factor analyses, which supported a hierarchical structure with four first-order factors and one second-order factor as the best-fitting model. Both versions of the scale demonstrated satisfactory internal consistency. Additionally, the external discriminant validity of the BAT-Brazil aligned with the Job Demands-Resources model. These findings provide initial evidence for the reliability and construct validity of the BAT-Brazil. (download full paper).