Abstract Background Out-of-hospital cardiac arrest (OHCA) in children is rare and can potentially result in severe neurological impairment. Our study aimed to identify characteristics of and factors associated with favourable neurological outcome following the resuscitation of children by the Swiss helicopter emergency medical service. Materials and methods This retrospective observational study screened the Swiss Air-Ambulance electronic database from 01-01-2011 to 31-12-2021. We included all primary missions for patients ≤ 16 years with OHCA. The primary outcome was favourable neurological outcome after 30 days (cerebral performance categories (CPC) 1 and 2). Multivariable linear regression identified potential factors associated with favourable outcome (odd ratio – OR). Results Having screened 110,331 missions, we identified 296 children with OHCA, which we included in the analysis. Patients were 5.0 [1.0; 12.0] years old and 61.5% (n = 182) male. More than two-thirds had a non-traumatic OHCA (67.2%, n = 199), while 32.8% (n = 97) had a traumatic OHCA. Thirty days after the event, 24.0% (n = 71) of patients were alive, 18.9% (n = 56) with a favourable neurological outcome (CPC 1 n = 46, CPC 2 n = 10). Bystander cardiopulmonary resuscitation (OR 10.34; 95%CI 2.29–51.42; p = 0.002) and non-traumatic aetiology (OR 11.07 2.38–51.42; p = 0.002) were the factors most strongly associated with favourable outcome. Factors associated with an unfavourable neurological outcome were initial asystole (OR 0.12; 95%CI 0.04–0.39; p < 0.001), administration of adrenaline (OR 0.14; 95%CI 0.05–0.39; p < 0.001) and ongoing chest compression at HEMS arrival (OR 0.17; 95%CI 0.04–0.65; p = 0.010). Conclusion In this study, 18.9% of paediatric OHCA patients survived with a favourable neurologic outcome 30 days after treatment by the Swiss helicopter emergency medical service. Immediate bystander cardiopulmonary resuscitation and non-traumatic OHCA aetiology were the factors most strongly associated with a favourable neurological outcome. These results underline the importance of effective bystander and first-responder rescue as the foundation for subsequent professional treatment of children in cardiac arrest.