BACKGROUND: In 2015, approximately 350,000 adults in the United States experienced nontraumatic out-of-hospital cardiac arrest and were treated by the emergency medical services (EMS) personnel. Despite recent increases, <40% of adults receive layman-initiated cardiopulmonary resuscitation (CPR), and <12% apply an automated external defibrillator before EMS personnel. AIM: To know the ability of the Medan city community in handling cardiac arrest for the first time and implementing the 2020 AHA basic life support (BLS). METHODS: This study used a descriptive method with a cross-sectional approach and was conducted in the city of Medan in the period July–October 2021. Sampling used cluster sampling and purposive sampling with inclusion and exclusion criteria. RESULTS: In this study, it was found that the majority of the people of Medan City had less knowledge about CPR in BLS. In this study, only respondents from Medan Marelan District were dominated by good knowledge by 80%. It was found that the people of Medan City have a good level of knowledge about these cardiac events, and the people of Medan City have a low level of knowledge about BLS and CPR. CONCLUSION: The ability of the people of Medan City in implementing BLS and CPR in BLS for cardiac events outside the hospital is still lacking.