Background &objectives: This study aimed to identify the preparation and self-confidence of school nurses to respond to emergent, acute or life-threatening health crises in individual students (asthma, anaphylaxis, diabetic crisis, seizures, cardiopulmonary failure, bleeding/fracture, and head/neck injury) in South Korea. Methods: This cross-sectional survey was done with 274 school nurses. Data was collected with self-administered questionnaires with nurse’s and school’s characteristics, preparation and self confidence in responding to the health crises from February 1, 2018 to July 31, 2018. Data were analyzed using descriptive statistics, t-test, ANOVA. Results: Most schools had response plan to the health crises in general, but 46.7% to 58.4% schools had the health crisis-specific plan. Equipment for the health crisis such as oxygen glucose monitoring device, automated external defibrillator, and cervical spine collar were available over 85% of the schools. However, bronchodilator delivery device, epinephrine auto-injector, and suction device showed limited availability. The self confidence in responding to the health crises ranged from 2.67 (managing seizure) to 3.55 (performing CPR) on a 5-point scale, and was significantly different by working years at hospitals for some health crises. Conclusions: Though schools have well established plan to response the health crises, the plan should be specific to each health crisis. As there was low self-confidence in responding to the health crises among school nurses, active interventions including systematic training and mentoring programs are recommended.