Background. The Coronavirus Disease (COVID-19) pandemic significantly disrupted regular health care services, mainly in the hospitals. Nurses soldiering on the battlefront of care of disaster response in the Philippines during the disease outbreak are at high risk of developing rapid-onset compassion fatigue. Notably, research is still needed to investigate the impact of compassion fatigue on various clinical areas and further develop a theory of compassion fatigue within the nursing context.Objectives. The study explored the concept of compassion as experienced by nurses directly caring for COVID-19 patients. The study further explored the experiences of nurses on compassion fatigue.Methods. This study employed qualitative methodology, specifically the constructivist grounded theory.Results. Thirty-four participants were included in the study. The narratives and voices of the nurses unfolded the following themes: (1) Acts of Compassion, (2) COVID-19 Pandemic: Nursing Challenges and Detours, (3) Nurses’ Compassion Fatigue, (4) Narratives of Opportunities: Thriving at the outset of COVID-19. All four concepts are linked to the multidimensional concept of compassion fatigue. A substantive theory, “Remon’s CF Theory in Nursing," is proposed based on the grounded experiences of nurses caring for COVID-19 patients related to compassion fatigue.Conclusion. Compassion Fatigue (CF) is a psycho-social phenomenon and occupational hazard affecting nursesdirectly caring for or in contact with COVID-19 patients. CF is a process that develops over time brought by prolonged enactment of compassion, the experience of empathic distress, and concurrence of organizational, contextual, and psychosocial factors. Nurses' CF can potentially affect safety and lead to poor nursing care, compromised work relations, and burnout. Nurse leaders' organizational and leadership commitment and support through up-to-date policies and continuous research on the topic are necessary to regain compassion among nurses. Likewise, reframing nurse compassion fatigue as an organizational and collective problem provides the larger perspective to further improve clinical practice and nurses’ welfare. Recommendations. Nurse leaders, hospital and COVID-19 facility administrators must ensure specific policiesand priorities that address issues causing and fueling nurse compassion fatigue, including frequency of exposure to traumatic events, lack of resources, and inadequate support system. The study further suggests conducting quantitative research to test the proposed theory and explore the relationship between organizational, psychosocial, and environmental context, compassion fatigue, and compassion-driven factors.