Purpose ‐ The purpose of this paper is to benchmark and measure the comparative efficiency of emergency medical services (EMS) in major US cities (populations greater than 100,000). In so doing, this paper aims to develop a benchmark that can be emulated by cities lagging in EMS efficiency. Also, it seeks to develop a profile of cities that are successful in providing highly efficient EMS as benchmarks. Design/methodology/approach ‐ Data envelopment analysis is used to measure the EMS efficiency of 127 selected large cities in the USA under the premise of a constant-return to scales method of service delivery. In addition, to identify factors influencing the US cities' EMS efficiency and then to predict their efficiency scores, a Tobit regression analysis is employed, which tended to result in a smaller standard error, a smaller bias, and a smaller mean squared error than ordinary least squares. Findings ‐ This paper examines whether more densely settled and populated areas have greater efficiency in delivering EMS. After controlling variables such as weather and climate, income, population growth, the age of a residential home, and geographic size of a city in land area, It is found that more densely settled, geographically large, and high income cities show more efficient provision of EMS. Originality/value ‐ This paper is the first to develop in a comprehensive way EMS benchmark performance standards for municipal governments and elaborate on a host of factors which are associated with the success of EMS deliveries. By setting such standards and identifying factors affecting EMS efficiency, this paper helps municipal governments to continuously improve their EMS and develop more efficient public policy.