Purpose: During the COVID-19 pandemic, nurses have faced many professional and ethical dilemmas and challenges along with bearing physical, mental, and emotional stress resulting from worrying about themselves or their family being infected and stigmatized. This stress can potentially lead to burnout and resignation. Professional resilience is crucial for nurses to cope with these adverse situations. This study aimed to investigate the process by which nurses adapt, change, and overcome challenges during the COVID-19 pandemic and ultimately demonstrate professional resilience. Methods: Descriptive phenomenology was applied. Semi-structured interviews were conducted with 11 nurses working in COVID-19 wards and intensive care units to collect data. Giorgi's phenomenological analysis method was employed. Results: Based on the interview responses, four major themes were identified: 1) balancing patient care, self-protection, and passing on experience; 2) providing timely pandemic team resources and social support; 3) nurses' perseverance amid social discourse and constrained lives; and 4) selfless dedication shaping nursing's pinnacle experiences. Conclusions In the face of a sudden pandemic, frontline nurses play a critical role in maintaining medical capacity. Consequently, they must balance their families, lives, and work while adapting to the impact of the pandemic and changing practices and procedures based on the development of the pandemic and policy demands. The study findings provide insights into the challenges and emotional experiences encountered by nurses during a sudden pandemic outbreak and can serve as a reference for developing strategies to help nurses overcome these challenges and enhance their professional resilience.