ObjectiveThe International Liaison Committee on Resuscitation has recommended improvements in training for neonatal resuscitation, highlighting the potential role of respiratory function monitors (RFMs). Our objective was to determine whether a manikin-based, standardised face mask ventilation training intervention using an RFM with a simple visual display reduced face mask leak.DesignMulticentre, before and after study. Participants and instructors were blinded to the RFM display during both assessment periods.ParticipantsHealthcare professionals working or training in a hospital providing maternity and neonatal services.InterventionAll participants underwent a training intervention on positive pressure ventilation using a modified, leak-free manikin and RFM. The intervention consisted of a demonstration of optimal face mask ventilation technique, training in RFM interpretation with corrective strategies for common scenarios and a period of deliberate practice. Each participant performed 30 s of positive pressure ventilation blinded to the RFM display before and after training.Main outcome measuresThe primary outcome was face mask leak (%) measured after training. Secondary outcome measures included expired tidal volume, inflating pressures and ventilation rate. Adjustments made to technique during training were an important qualitative outcome.ResultsFour hundred and fourteen participants were recruited over a 13-month period from April 2022, and 412 underwent analysis. Median (IQR) face mask leak before training was 31% (10–69%) compared with 10% (6–18%) after training (p<0.0001). Improvements were noted across all other ventilation parameters.ConclusionStandardised face mask ventilation training using an RFM with simple visual feedback led to a significant reduction in leak.