Purpose: This study aimed to understand nurses' lived experiences of caring for patients with COVID-19. Methods: The phenomenological research method was used. The study participants were 16 Korean nurses who had experiences in caring for patients with COVID-19 in clinical settings. Data was collected using one-on-one in-depth interviews, from June 30 to September 30, 2020. During the interview, the quarantine rules were observed. Results: The study derived four themes clusters and thirty-eight sub themes. Four theme clusters were identified, i.e., 'a repetitive sense of crisis', 'enduring a drastic change,' 'sacrifice of personal life,' and 'pride in nursing'. The nurses' experiences of caring for patients with COVID-19 were an uneasy, unfamiliar, and threatening experiences for an individual, but it is an opportunity for a nursing organization to renew. Accordingly, it was found that nurses faithfully fulfill their individual roles with a vocation and responsibility. Conclusion: The study provides an in-depth understanding of the situational, psychological, and environmental aspects of challenges facing nurses in the pandemic situation. Based on the findings, institutional follow-up measures should be provided to establish support systems for better nursing care. In addition, studies are needed to track nurses' experiences in the prolonged COVID-19 situation.