Background High work pressure and complex problems during the COVID-19 pandemic caused nursing staff, including first-line managers, experienced burnout. Objective This study aims to explore burnout experienced of first-line managers during the COVID-19 pandemic. Methods This qualitative descriptive study used thematic analysis. Twelve first-line managers were selected using purposive sampling from two government hospitals, designated as COVID-19 referral centres in Jakarta and Depok, Indonesia. Data were collected through semi-structured online face-to-face interviews using ZOOM meeting video with a guideline interview. Results Exploration of first-line manager’s burnout revealed three themes: 1) unpreparedness, 2) impact on wellbeing, and 3) resilience. Conclusion The first-line managers experienced burnout during the pandemic due to obstacles in implementing management roles and functions accompanied. Their burnout was caused by the unpreparedness of both the hospital management and the community. Their burnout has an impact on their emotional and physical well-being. By this time, the first-line manager’s resilience was formed because they used adaptive coping mechanisms and had a good support system. The experience during COVID-19 should be a lesson learned to strengthen the healthcare system in the future. Risk management mitigation must be systematically and routinely performed.