Introduction
Burnout syndrome (BS) in healthcare professionals (HCP) has been a major concern, and even more so during the coronavirus disease 2019 (COVID-19) pandemic. The need for adequate tools to assess BS is urgent. The objective of this study was to validate the Brazilian Portuguese version of the Copenhagen Burnout Inventory (CBI) in HCP.

Methods
The sample comprised 1,054 Brazilian HCP. Data were collected for 1 month (May-2020 to June-2020) using an online self-administered questionnaire.

Results
All three CBI dimensions demonstrated optimal reliability. All consistency measures attained values > 0.90. Split-half correlation values with Spearman-Brown reliability were higher than 0.8. The parallel analysis suggested two factors: personal burnout (PB) and work-related burnout (WB) items were associated with factor 1, and client-related burnout (CB) items were associated with factor 2.

Conclusion
Our study corroborates the validity of the Brazilian Portuguese version of the CBI, pointing to a close relation between PB and WB in HCP. A public domain tool with evidence quality to ensure sufficient content validity can aid in burnout evaluation and encourage both expansion of the research field and accurate detection and treatment of this syndrome in Brazilian HCP.