Background There is insufficient knowledge of out-of-hospital cardiac arrest (OHCA) in the very young. Objectives This nationwide study sought to examine age-stratified OHCA characteristics and the role of parental socioeconomic differences and its contribution to mortality in the young population. Methods All OHCA patients in Denmark, ≤21 years of age, were identified from 2001 to 2010. The population was divided into infants (<1 year); pre-school children (1–5 years); school children (6–15 years); and high school adolescents/young adults (16–21 years). Multivariate logistic regression analyses were used to investigate associations between pre-hospital factors and study endpoints: return of spontaneous circulation and survival. Results A total of 459 individuals were included. Overall incidence of OHCA was 3.3 per 100,000 inhabitants per year. The incidence rates for infants, pre-school children, school children and high school adolescents were 11.5, 3.5, 1.3 and 5.3 per 100,000 inhabitants. Overall bystander CPR rate was 48.8%, and for age groups: 55.4%, 41.2%, 44.9% and 63.0%, respectively. Overall 30-day survival rate was 8.1%, and for age groups: 1.4%, 4.5%, 16.1% and 9.3%, respectively. High parental education was associated with improved survival after OHCA (OR 3.48, CI 1.27–9.41). Significant crude difference in survival (OR 3.18, CI 1.22–8.34) between high household incomes vs. low household incomes was found. Conclusion OHCA incidences and survival rates varied significantly between age groups. High parental education was found to be associated with improved survival after OHCA.