The most appropriate airway device for use in EMS systems staffed by basic skilled EMTs with (EMT-Ds) or without (EMT-Bs) defibrillation capabilities is still a matter of debate. The purpose of this study was to assess the feasibility, safety and effectiveness of the Esophageal Tracheal Combitube (ETC) when used by EMT-Ds in cardiorespiratory arrest patients of all etiologies. The EMTs had automatic external defibrillator (AED) training but no prior advanced airway technique skills. The prehospital intervention was reviewed using the EMTs cardiac arrest report, the AED tape recording of the event and the assessment of the receiving emergency physician. The patients' hospital records and autopsy report were reviewed in search of complications. Eight hundred and thirty-one adult cardiac arrest patients were studied. Placement was successful in 725 (95.4%) of the 760 patients where it was attempted and ventilation was successful in 695 (91.4%). Immediate complications encountered, but not necessarily related to the use of the ETC, were; subcutaneous emphysema (18), tension pneumothorax (5), blood in the oropharynx (15), and swelling of the pharynx (three). An autopsy was done in 133 patients; no esophageal lesions or significant injury to the airway structures were observed. Our results suggest that EMT-Ds can use the ETC for control of the airway and ventilation in cardiorespiratory arrest patients safely and effectively.