Background and Objectives: Out-of-hospital cardiac arrest (OHCA) and survival is a pressing matter all around the world. Despite years of research and great strides and advancements, survival remains alarmingly low. The aim of this study was to measure the survival and characteristics of patients having an OHCA in Slovenia, with an in-depth look at how the bystanders affect the return of spontaneous circulation (ROSC) and survival of OHCA. Materials and Methods: In this observational cross-sectional prospective study, we enrolled patients between 1 September 2022 and 30 November 2022, with a follow-up period of 1 month. All OHCAs attended by the emergency medical services were included. Data were collected and analyzed according to the Utstein 2015 reporting template. Independent predictors of ROSC and 30-day survival or survival were explored using ridge regression. Results: ROSC was achieved in 41% of cases where resuscitation was attempted. The overall 30-day survival rate where resuscitation was attempted was 14%. In 13% of all cases where resuscitation was attempted, patients had a favorable neurological outcome. Using our prediction model, we found that defibrillation under 20 min and ventricular fibrillation as an initial rhythm improves survival, whilst no defibrillation and bystander full cardiopulmonary resuscitation negatively predicted survival. Conclusions: Slovenia has OHCA 30-day survival comparable to the rest of the European Union. The favorable neurological outcome is high. Our data show that bystanders do not significantly improve survival. This represents an untapped potential of general public education in cardiopulmonary resuscitation and automatic external defibrillator use. Following good practices from abroad and improving layperson CPR knowledge could further improve OHCA survival.