Abstract Background Prehospital trauma care is stressful and requires multi-professional teamwork. A decrease in the number of accident victims ultimately affects the routine and skills and underlines the importance of effective training. Standardized courses, like PHTLS, are established for health care professionals to improve the prehospital care of trauma patients. The aim of the study was to investigate the subjective safety in prehospital trauma care and learning progress by paramedics in a longitudinal analysis. Methods This was a prospective intervention trial and part of the mixed-method longitudinal EPPTC-trial, evaluating subjective and objective changes among participants and real patient care as a result of PHTLS courses. Participants were evaluated with pre/post questionnaires as well as one year after the course. Results We included 236 datasets. In the pre/post comparison, an increased performance could be observed in nearly all cases. The result shows that the expectations of the participants of the course were fully met even after one year (p = 0.002). The subjective safety in trauma care is significantly better even one year after the course (p