Purpose This study aimed to examine the moderating effect of calling on the relationship between post-traumatic stress and turnover intention among nurses caring for COVID-19 patients. Methods Data were collected from 151 nurses caring for COVID-19 patients at three university hospitals located in D City. Participants completed selfreported online surveys on post-traumatic stress (IES-R-K), calling (CVQ-R), and turnover intention. Descriptive statistics, t-tests, one-way ANOVA, Scheffé test, Pearson's correlation coefficients, and hierarchical multiple regression were performed using SPSS 25.0. Results The mean scores of post-traumatic stress, calling, and turnover intention were 0.83±0.70, 1.51±0.71, and 2.89±1.10, respectively. Post-traumatic stress had positive correlations with calling (r=.20, p=.011) and turnover intention (r=.29, p=.001), whereas calling had a negative correlation with calling and turnover intention (r=-.17, p=.029). Calling had a moderating effect in the relationship between post-traumatic stress and turnover intention (β=-.16, p=.032). Conclusion Calling has a moderating effect on the relationship between post-traumatic stress and turnover intention. Therefore, developing and implementing a program is necessary to strengthen nurses' perceptions of calling to prevent nurses with post-traumatic stress from leaving their jobs.