Schools are important location for improving OHCA outcome by public advertisement, CPR education, or AED. But there is no sufficient epidemiological data about OHCA in school. We aimed to show incidence ad outcome of OHCA in school. We used nationwide, population-based OHCA registry from 2008~2013 in Korea. Presumed cardiac origin arrest occurred in school were included. Victims were categorized as student, faculty, and visitors. Average annual incidence of OHCA in school was calculated based on per 100,000 person or per 1000 schools. During the period, 318 cardiac origin OHCA occurred in school. Overall, the annual incidence was 2.26/1000 school and 0.28/100,000 person in student and faculty. median age was 16.7 in student and 52.1 in non-student. OHCA of student was more witnessed, was given more bystander CPR, and had more shockable rhythm compared to non-student. In student OHCA, 24 (18.5%) occurred during sports activity while 88 46.8%) occurred in non-students. Survival hospital discharge 50 (38.5%) vs. 59 (31.4%) in student and non-student group but non-student group had better neurological outcome of 28 (14.9%) than 13 (10.0%) in student group. Overall incidence of OHCA in school is low. About 40% of victims were visitors. 1/3 of OHCA occurred during sports activity and had higher shockable rhythm. School AED program can be improved based on these findings.