BACKGROUND There is increasing interest for quality measurement in health care services; pre-hospital emergency medical services (EMS) included. However, attempts of measuring the quality of physician-staffed EMS (P-EMS) are scarce. The aim of this study was to develop a set of quality indicators for international P-EMS to allow quality improvement initiatives. METHODS A four-step modified nominal group technique process (expert panel method) was used. RESULTS The expert panel reached consensus on 26 quality indicators for P-EMS. Fifteen quality indicators measure quality of P-EMS responses (response-specific quality indicators), whereas eleven quality indicators measure quality of P-EMS system structures (system-specific quality indicators). CONCLUSIONS When measuring quality, the six quality dimensions defined by The Institute of Medicine should be appraised. We argue that this multidimensional approach to quality measurement seems particularly reasonable for services with a highly heterogenic patient population and complex operational contexts, like P-EMS. The quality indicators in this study were developed to represent a broad and comprehensive approach to quality measurement of P-EMS. CONCLUSIONS The expert panel successfully developed a set of quality indicators for international P-EMS. The quality indicators should be prospectively tested for feasibility, validity and reliability in clinical datasets. The quality indicators should then allow for adjusted quality measurement across different P-EMS systems.