This randomized controlled trial evaluated the effect of an interactive demonstration-based cyber health education intervention on digital health literacy and information security awareness among high school students. Two public high schools were randomly assigned to the intervention and control groups. Students in the intervention group received a three-week education program consisting of one 30-40-minute session per week. The program included interactive presentations, demonstrations, scenario-based activities, group discussions, and question-and-answer sessions focusing on digital health literacy and information security. Students in the control group continued their routine school education without receiving the intervention during the study period. Digital health literacy and information security awareness were assessed at baseline, immediately after the intervention, and at a four-week follow-up.