Introduction The Covid-19 pandemic brought new challenges to healthcare workers, promoting fatigue and professional exhaustion, leading frequently to burnout. Objectives Assess the levels of Burnout among nurses and nursing assistants of a tertiary hospital; compare the levels of burnout between these two groups and identify the influence of sociodemographic and professional factors in the studied groups. Methods Quantitative, transversal, descriptive and correlational study. Data was collected through a questionnaire. Descriptive and inferential analysis was performed. Results During the pandemic, nurses and nursing assistants presented high levels of personal, work-related and client-related Burnout, mainly due to professional, contextual and personal factors. Conclusion High levels of Burnout were found in nurses and nursing assistants. Institutions should monitor and control burnout levels regularly. Protocols and instruments must be developed to ensure healthcare professionals maintain good levels of mental health. Keywords: Burnout; Pandemic; Nurses; Operational Assistants, Occupational Health.