Purpose: The purposes of this study was to identify the nurses' experiences of prolonged mask wearing in the context of COVID-19. Methods: This study was a qualitative study that used the content analysis method. Data were collected using focus group interviews with 18 nurses at a tertiary general hospital from April 13 to 27, 2023. Results: Five themes and 15 sub-themes emerged through qualitative content analysis. The themes included: “Mandatory or optional experience of wearing a mask unrelated to COVID-19”, “Mandatory KF94 masks during the COVID-19 pandemic”, “Multifaceted changes in life due to mandatory mask wearing”, “Unexpected benefits of wearing a mask”, “Difficulties with wearing masks continue even after the COVID-19 pandemic”. Conclusion: This study confirmed the discomfort and difficulties of prolonged mask wearing among nurses in the context of COVID-19. Our findings suggest that there is a need for organizational and national support for nurses who are required to continue wearing masks after the COVID-19 pandemic.