Purpose: The purpose of this study was to identify the effects of the perception and attitude toward disaster on the disaster preparedness competency of dementia center workers. Methods: The study design was a descriptive correlational survey of workers in dementia centers in South Korea. Data on attitude, perception, and disaster preparedness competency were collected using online and offline surveys. The data were analyzed with descriptive statistics, independent t-test, one-way ANOVA, Pearson correlation coefficient, and multiple regression. Results: The mean scores of attitude, perception, and disaster preparedness competency were 3.57±0.39, 3.42±0.35, and 2.92±0.53, respectively. The impacting factors on disaster preparedness competency were disaster perception(β=.35, p<.001) and profession of nurse(β=0.32, p<.001) with 26% of explanatory power. Conclusion: Promoting perception toward disaster and professional disaster education is recommended to improve the disaster preparedness competency of workers in dementia centers.