In this prospective study, we used two full-scale prehospital trauma scenarios (severe chest injury and severe head injury) and checklists of specific actions, reflecting essential actions for a safe treatment and successful outcome, were used to assess performance of postinternship physician graduates of the Advanced Trauma Life Support (ATLS) course. In the first 36 participants, simulated training followed basic training in airway and breathing management, whereas in the next 36 participants, 45 min of simulative training in airway management using the Air-Man simulator (Laerdal, Norway) were added before performing the study scenarios. The content of training was based on common mistakes performed by participants of the first group. After the change in training, the number of participants not performing cricoid pressure or not using medication during intubation decreased from 55% (20 of 36) to 8% (3 of 36) and from 42% (15 of 36) to 11% (4 of 36), respectively (P < 0.05). The number of participants not holding the tube properly before fixation decreased from 28% (10 of 36) to 0% (0 of 36) (P < 0.05). In the severe head trauma scenario, performed by 15 of 36 participants in each group, the incidence of mistakes in the management of secondary airway or breathing problems after initial intubation decreased from 60% (9 of 15) to 0% (0 of 15) (P < 0.05). The present study highlights problems in prehospital trauma management, as provided by the ATLS course. It seems that graduates may benefit from simulation-based airway and breathing training. However, clinical benefits from simulation-based training need to be evaluated.