Background The COVID-19 pandemic has placed an unprecedented burden on nurses who have been at the forefront of patient care. The continuous exposure to suffering, death, and overwhelming demands has the potential to lead to compassion fatigue, a state of emotional, physical, and cognitive exhaustion. Research aim The study aimed to explore and understand the phenomenon of compassion fatigue in nurses as the effect of the COVID-19 pandemic. Research design A constructivist grounded theory design was used. Participants and research context (...) The research data were collected from 20 nurses who had been employed in pandemic clinics in Turkey for a minimum of 6 months. Data were collected using a two-step approach: purposeful sample selection followed by theoretical sample selection. Individual interviews were conducted via an online platform with participants who consented to participate in the study from January 16th to April 28th, 2022. The collected data underwent initial, focused, and theoretical coding for analysis. The research findings were reported following the Consolidated Criteria for Reporting Qualitative Research guidelines. Ethical considerations Ethical approval for the study was received from Non-Interventional Clinical Research Ethics Committee. The study was conducted following the Declaration of Helsinki. Findings The study identified a core category, namely the desire to provide the best care, which was accompanied by five main categories: causes, symptoms, consequences, coping methods, and the benefits of coping methods. Conclusion During the pandemic process, nurses have experienced compassion fatigue due to various factors and have seen its symptoms. Nurses have developed various coping mechanisms individually. However, they have not indicated any institutional-level support. It has become necessary to plan nurse-centered comprehensive interventions that will reduce compassion fatigue. (shrink)