Purpose: This study aimed to examine the effects of a disaster nursing education program using the Korean Triage and Acuity Scale (KTAS) on nursing students’ competency in emergency patient triage, core competencies, confidence in disaster nursing, and self-efficacy in disaster response. Methods: This study utilized a nonequivalent control group design. The experimental group (n=25) participated in a disaster nursing education program that incorporated the KTAS, whereas the control group (n=27) did not receive any intervention. Data were analyzed using descriptive statistics and t-tests. Results: The two groups differed significantly in both competency in emergency patient triage (t=3.47, p=.001) and confidence in disaster nursing (t=2.51, p=.015). Conclusions: This study indicates that a disaster nursing education program using the KTAS, a tool currently employed in clinical practice, rather than theory-based instruction alone, contributed to enhancing nursing students’ practical competencies. Such training can improve the emergency patient triage and confidence in disaster nursing required in emergency situations, ultimately enabling future nurses to better protect the lives and health of individuals affected by disasters.