Introduction: The Copenhagen Burnout Inventory was developed to overcome what some authors have proposed as potential limitations of existing burnout measures. Specifically, the Copenhagen Burnout Inventory measures the main component of burnout (i.e. exhaustion) in three domains: personal-, work- and patient-related. Additionally, some authors have argued the necessity to have available a global burnout index.Material and Methods: This study followed a cross-sectional design in a sample of Portuguese physicians (n = 1348). A confirmatory factor analyses was conducted and the Copenhagen Burnout Inventory´s three-factor structure was tested. In addition, a model with a 2nd order factor was tested with the goal of achieving a one-factor structure that would allow a global burnout index.Results: The confirmatory factor analyses showed a good model fit for both the three-factor and one-factor model, having the latter a significant better fit. The Copenhagen Burnout Inventory showed good psychometric properties for both structures, with good reliability according to Chronbach`s alphas and average variance extracted between factors. The Copenhagen Burnout Inventory I was statistically and positively correlated with depression, anxiety and stress symptoms, as well as rumination, and negatively correlated with life satisfaction.Discussion: The current study shows that the Copenhagen Burnout Inventory is a psychometrically valid measure of burnout in Portuguese physicians, and contributes with an instrument able to produce a global index of burnout. This measure provides comprehensive information on different dimensions associated with the development of burnout, as well as presents a global burnout score. Results show that participants who had more burnout also presented higher levels of depressive, anxiety and stress symptoms, as well as present more ruminative thinking, and less life satisfaction.Conclusion: The Copenhagen Burnout Inventory is a psychometrically valid measure of burnout that allows for exploratory studies on the overall level of exhaustion, thus making it possible the comparison between groups in a way that is not restricted to occupation specific aspects.