The purposes of this study are to identify differences in subjective disaster perception, preparedness, management and disaster nursing competency between Korean and Japanese hospital nurses and to identify the factors affecting disaster nursing competency. The study subjects were 197 hospital nurses who were working at general hospitals in Korea (n=117) and Japan (n=80). An independent t-test, ANOVA, χ2-test, ANCOVA, correlation analysis and multiple regression analysis were used to compare disaster nursing competency using SPSS WIN 21. Disaster nursing competency were measured as 3.22±0.64 for Korean nurses and 2.81±0.84 for Japanese nurses. A significant difference was found in disaster perception, disaster preparedness and main authority of disaster management, organizational performance between the two countries. The factors affecting disaster nursing competency include career, country, main authority of disaster management, disaster preparedness, safety perception, disaster experience, all of which accounted for 30% of the variance in disaster nursing competency. The findings from this study will provide the foundation for nursing education to develop disaster nursing competency among hospital nurses.