Introduction: Accidents including traffic accidents can occur anywhere, anytime. Around the world, 1.2 million die each year from accidents, and 50 million are injured. Indonesia has the fifth highest rate of accidents. The conse- quences of unexpected accidents can be life threatening, on an average one traffic accident occurs every 0.5 minutes. Cardiac Pulmonary Resuscitation (CPR) is an individual's skill to save a person's life. This is very important in the first five minutes in a victim's life in many emergency situations. In an emergency, bystander including children in the high school is expected to perform a core role in carrying out CPR. The aim of this study is to determine CPR knowl- edge in High School. Methods: The type of research is a pre-experimental research by approaching the One Group Pre and Post Test Design. Intervention study using pre and post-test validated questionnaire was conducted among 40 students of Tunas Husada high school that were randomly selected. Data analysis was performed with the Macnemar test. Results: The results of the study obtained p= 0.000 which is less than 0.05, so result of the study reveal significant difference in knowledge before and after health education. Thus, there is an effect of health education in increasing knowledge of first aid in traffic accidents among students at Tunas Husada high school, Kendari. Conclusion: This study identify that majority students has poor knowledge on CPR. Therefore, implementation of basic life-support training for all school children is recommenced.