Bystander cardiopulmonary resuscitation improves survival after out-of-hospital cardiac arrest. This study aimed to assess the effectiveness of a basic life support (BLS) educational course given to 110 middle school children, using a pretest posttest design. In the pretest, students were asked to demonstrate BLS on a manikin to simulate a real-life scenario. After the pretest, a BLS training course of two sessions was provided, followed by posttest on the same manikin. Students were assessed using an observational sheet based on the American Heart Association's BLS guidelines. In the pretest, students showed significant weakness in the majority of guidelines. In the posttest, they demonstrated significant improvement in their BLS skills. BLS training in the middle school was effective, considering the lack of previous skills. It is recommended that BLS education be compulsory in the school setting.