Aim To investigate bystanders’ CPR involvement in out-of-hospital cardiac arrest (OHCA) events, their current knowledge regarding OHCA and BLS measures, their willingness to learn BLS measures with the usage of AEDs, as well as current practices. Methods This cross-sectional study included: data regarding all OHCA events treated at the Emergency Medical Service of Canton Sarajevo between January 2015 and December 2019, and an online anonymous questionnaire that examined knowledge, attitudes and practices regarding basic life support (BLS) and automated external defibrillators (AEDs). Results A total of 328 (24.0 %) of 1362 OHCA events achieved the return of spontaneous circulation (ROSC). OHCA incidence was 62/100.000 inhabitants per year. Male gender (p=0.043) and younger age (p