Purpose: This study aimed to investigate the effect of positive psychological capital, empathy ability, and stress coping style on psychiatric ward nurses’ compassion fatigue. Methods: Data were collected using structured questionnaires for 140 psychiatric ward nurses. The data were analyzed using t-test, one-way ANOVA, and hierarchical regression. Results: The variable predictors of compassion fatigue were as follows: positive psychological capital (β=-.35, p<.001), empathy ability (β=.32, p<.001), and passive coping (β=.25, p=.004). These factors explained 27% of compassion fatigue, and psychological capital was found to have the greatest influence among these variables. Conclusion Positive psychological capital, empathy ability, and passive coping are important factors influencing nurses’ compassion fatigue in psychiatric wards. It is necessary to develop interventions and appropriate coping styles that strengthen positive psychological capital to prevent and reduce nurses’ compassion fatigue in psychiatric wards. In addition, it is necessary to identify the required level of empathy ability to maintain a therapeutic relationship.