Background: The time from injury to treatment is considered as one of the major determinants for patient outcome after trauma. Previous studies already attempted to investigate the correlation between prehospital time and trauma patient outcome. However, the outcome for severely injured patients is not clear yet, as little data is available from prehospital systems with both Emergency Medical Services (EMS) and physician staffed Helicopter Emergency Medical Services (HEMS). Therefore, the aim was to investigate the association between prehospital time and mortality in polytrauma patients in a Dutch level I trauma center. Methods: A retrospective study was performed using data derived from the Dutch trauma registry of the National Network for Acute Care from Amsterdam UMC location VUmc over a 2-year period. Severely injured polytrauma patients (Injury Severity Score (ISS) ≥ 16), who were treated on-scene by EMS or both EMS and HEMS and transported to our level I trauma center, were included. Patient characteristics, prehospital time, comorbidity, mechanism of injury, type of injury, HEMS assistance, prehospital Glasgow Coma Score and ISS were analyzed using logistic regression analysis. The outcome measure was in-hospital mortality. Results: In total, 342 polytrauma patients were included in the analysis. The total mortality rate was 25.7% (n = 88). Similar mean prehospital times were found between the surviving and non-surviving patient groups, 45.3 min (SD 14.4) and 44.9 min (SD 13.2) respectively (p = 0.819). The confounder-adjusted analysis revealed no significant association between prehospital time and mortality (p = 0.156). Conclusion: This analysis found no association between prehospital time and mortality in polytrauma patients. Future research is recommended to explore factors of influence on prehospital time and mortality.