Training laypeople to give first aid in emergency situations and offer basic life support (BLS) is crucial in order to save lives and avoid sequelae. The objective was to identify laypeople's knowledge about BLS. Structured interviews were performed using non-technical language. The sample consisted of 385 subjects. Most (57.1%) were women with complete secondary-level education and incomplete higher education (53.7%). It was verified that only 9.9% know the mouth-to-mouth ventilation maneuver; 84.2% knew the chest compression technique (CCT), and 79.9% of these knew its purpose. Only 14.5% know how to position the victim to perform CCT; 82.4% reported a frequency below 60 CCT minute. Since they do not have adequate information and foundations regarding the stages of BLS, laypeople can give incorrect first aid to victims, which can harm resuscitation.432334341