OBJECTIVE: Severe blunt trauma injuries are known to affect more than 12,000 individuals in the United Kingdom (UK) each year, the majority of whom require very intensive and expensive emergency care. A number of studies have estimated the direct and indirect cost of severe trauma injuries in different countries. The objective of this study is to provide an estimate of the direct medical cost of severe blunt trauma in the UK. METHODS: A bottom-up costing exercise was undertaken to estimate the direct medical cost of a typical severe blunt trauma patient involved in a motor vehicle traffic accident from the perspective of the UK NHS. The typical severe blunt trauma patient used in the analysis was adapted from previously published literature to be representative of patients presenting at UK trauma centers. UK-specific unit costs were applied to the different items of resource use identified in order to estimate the direct medical cost of a severe blunt trauma patient in the UK. RESULTS: The estimated direct medical cost of a severe blunt trauma patient in the UK is £48,813. The main cost drivers are ICU stay (56%) and surgical intervention (32%). This estimate is similar to those reported in the literature. The incidence of severe trauma in UK is estimated to be four per one million per week (approximately 12,000 per year). This indicates that the total direct cost to the UK NHS of severe trauma is around £0.6 billion per year. Given that published studies suggest that the direct medical costs of trauma represent about 25% of the total cost, the total cost of trauma in the UK would be around 2.4 billion per year. CONCLUSIONS: The direct medical cost of trauma represents a substantial economic burden to society. Initiatives that reduce this burden (e.g. prevention, treatment) are welcomed.