Objective To determine the cost-utility of a multi-professional simulation training programme for obstetric emergencies–Practical Obstetric Multi-Professional Training (PROMPT)–with a particular focus on its impact on permanent obstetric brachial plexus injuries (OBPIs). Design A model-based cost-utility analysis. Setting Maternity units in England. Population Simulated cohorts of individuals affected by permanent OBPIs. Methods A decision tree model was developed to estimate the cost-utility of adopting annual, PROMPT training (scenario 1a) or standalone shoulder dystocia training (scenario 1b) in all maternity units in England compared to current practice, where only a proportion of English units use the training programme (scenario 2). The time horizon was 30 years and the analysis was conducted from an English National Health Service (NHS) and Personal Social Services perspective. A probabilistic sensitivity analysis was performed to account for uncertainties in the model parameters. Main outcome measures Outcomes for the entire simulated period included the following: total costs for PROMPT or shoulder dystocia training (including costs of OBPIs), number of OBPIs averted, number of affected adult/parental/dyadic quality adjusted life years (QALYs) gained and the incremental cost per QALY gained. Results Nationwide PROMPT or shoulder dystocia training conferred significant savings (in excess of £1 billion ($1.5 billion)) compared to current practice, resulting in cost-savings of at least £1 million ($1.5 million) per any type of QALY gained. The probabilistic sensitivity analysis demonstrated similar findings. Conclusion In this model, national implementation of multi-professional simulation training for obstetric emergencies (or standalone shoulder dystocia training) in England appeared to both be cost-saving when evaluating their impact on permanent OBPIs.