Background: Natural and man-made disasters have significant effects on the physical, psychological, and emotional health of society. Nurses play an essential role in disaster management. Therefore, nurses should have specific core competencies to provide care for affected people during disaster situations. Objectives: This study aimed to assess hospital nurses’ disaster competencies in such situations. Methods: This cross-sectional, descriptive study was conducted using a self-report questionnaire that included 50 questions on NCDS (Nurse Competence Disaster Scale) in four domains. The questionnaires were distributed among 142 nurses working in three teaching hospitals in Kerman, Iran, in 2018. Results: The average percentage scores of nurses on their responses to questions in the domains of management, ethical aspects, personal aspects, and technical aspects of disaster competencies were 39. 76%, 19. 53%, 32. 02%, and 75. 06%, respectively. In multiple regression analysis, nurses’ participation in maneuvers and their work experience exerted the strongest influence on disaster nursing core competencies. Nurses who had practice during maneuvers had higher competency scores by 19. 63 units than those who had no practice (p=0. 0001). Moreover, the competency scores of nurses with more than 11 years of work experience were higher by 11. 42 units than the others (p=0. 0001). Conclusion: According to the results of the current study, strategies such as disaster drills and continuing education programs need to be developed for nurses to improve their disaster core competency.