INTRODUCTION: INTRODUCTION: Out-of-hospital cardiac arrest (OHCA) is a major public health problem, due to the low survival rate, which largely depends on the timely response of both, emergency medical service (EMS) team and bystanders and their provision of basic life support (BLS). In the Republic of Croatia, about 8,000 people experience OHCA per year. The actual effectiveness of out-of-hospital cardiopulmonary resuscitation (CPR) is still unknown. Therefore, the purpose of this paper is to try to identify factors associated with the outcome of CPR after OHCA and to present and interpret the data so that they can influence the improvement outcomes for people with OHCA. RESEARCH GOAL: The main objective is to show the success of CPR after OHCA in the EMS Department of Primorje-Gorski Kotar County - Delnice branch over the last 5 years. The specific objectives are to determine the presence of eyewitnesses in the incident, to determine the recognition of cardiac arrest by the dispatcher and to give instructions for CPR, and to show the most common initial rhythm when the emergency team arrives. RESPONDENTS AND METHODS: Data were collected from the EMS Department database. Data from the standardized Utstein form on the number of interventions, gender, age, presence of eyewitnesses, initiation of CPR by eyewitnesses, occurrence of ROSC, initial rhythm, giving instructions for CPR by the dispatcher, defibrillation, and response time of the EMS team from receipt calls to the dispatcher to the venue were used. The results are presented graphically and tabularly, and statistically processed in the statistical data processing program STATISTICA 12, Tibco, California. Statistical significance was set at p<0.005. RESULTS: In the five-year period, EMS Department of Primorje-Gorski Kotar County - Delnice branch had 215 interventions, of which the majority were male in the 80-89 age group. The success rate of resuscitation in registered cases is 9%, OHCA is witnessed in less than 50% of cases, while instructions for CPR are given by dispatchers in all registered confirmed cases of OHCA. The most common initial rhythm is asystole (84%). CONCLUSION: The success of resuscitation (9%) is significantly lower than expected (50%), as well as the presence of eyewitnesses during OHCA. The main factors that influence these results are in accordance with the research conducted so far (male sex, older age, cardiac arrest without eyewitnesses, initial rhythm-asystole, response time), and the results are additionally contributed by the geographical area and demographic structure.