Purpose: The purpose of this study was to investigate post-traumatic stress, job stress, fatigue, and social support of nurses in direct care for COVID-19 patients and to identify the factors affecting post-traumatic stress among the nurses. Methods: The participants were 150 nurses from three hospitals. Data were collected from September 11, 2020 to September 21, 2020. The data were analyzed with SPSS/WIN/25.0 program. Results: The mean score of post-traumatic stress was 22.27±15.49 (range 0~88). The percentage of high risk group of post-traumatic stress was 35.3%, risk group was 20.0%, normal group was 44.7%. Post-traumatic stress showed statistically significant differences according to quarantined experience (t=2.15, p=.033), and provision of COVID-19 manual (t=-2.40, p=.026). Post-traumatic stress was positively correlated with job stress (r=.48, p<.001), and fatigue (r=.58, p<.001), and it was negatively correlated with social support (r=-.22, p=.005). Job stress was positively correlated with fatigue (r=.74, p<.001), and it was negatively correlated with social support (r=-.17, p=.030). Fatigue and social support (r=-.17, p=.029) had a negative correlation. The results of regression analysis showed that the factors affecting post-traumatic stress included fatigue (β=.56, p<.001), provision of COVID-19 manual (β=-.24, p<.001), and quarantined experience (β =.18, p=.006) and that the total explanatory power was 42.0%. Conclusion: In this study, fatigue, provision of COVID-19 manual, and quarantined experience were found as influential factors of post-traumatic stress among nurses in direct care for COVID-19 patients. Therefore, development of the intervention for reducing the fatigue should consider to prevent post-traumatic stress in nurses. Also, provision of COVID-19 manual for nurses and psychological intervention program for nurses experienced quarantine are necessary.