WHAT'S KNOWN ON THIS SUBJECT: High-fidelity simulation improves individual skills in neonatal resuscitation. Usually, training is performed in a simulation center. Little is known about the impact of in situ training on overall team performance. WHAT THIS STUDY ADDS:In situ high-fidelity simulation training of 80% of a maternity' s staff significantly improved overall team performance in neonatal resuscitation (technical skills and teamwork). Fewer hazardous events occurred, and delay in improving the heart rate was shorter. abstract OBJECTIVES: High-fidelity simulation is an effective tool in teaching neonatal resuscitation skills to professionals. We aimed to determine whether in situ simulation training (for ∼80% of the delivery room staff) improved neonatal resuscitation performed by the staff at maternities. METHODS:A baseline evaluation of 12 maternities was performed: a random sample of 10 professionals in each unit was presented with 2 standardized scenarios played on a neonatal high-fidelity simulator. The medical procedures were video recorded for later assessments. The 12 maternities were then randomly assigned to receive the intervention (a 4-hour simulation training session delivered in situ for multidisciplinary groups of 6 professionals) or not receive it. All maternities were evaluated again at 3 months after the intervention. The videos were assessed by 2 neonatologists blinded to the pre-/postintervention as well as to the intervention/control groups. The performance was assessed using a technical score and a team score. RESULTS:After intervention, the median technical score was significantly higher for scenarios 1 and 2 for the intervention group compared with the control group (P = .01 and 0.004, respectively), the median team score was significantly higher (P , .001) for both scenarios. In the intervention group, the frequency of achieving a heart rate .90 per minute at 3 minutes improved significantly (P = .003), and the number of hazardous events decreased significantly (P , .001). CONCLUSIONS:In situ simulation training with multidisciplinary teams can effectively improve technical skills and teamwork in neonatal resuscitation. Pediatrics 2014;134:e790-e797