In Sweden, as in many other countries, paramedics or nurses constitute the majority of prehospital personnel. If tasks usually performed by doctors are to be performed by these personnel, there is a need for guidelines and triage in the handling of medical emergencies. We describe an information management system used in ambulances for data communication, documentation, triaging and presentation of checklists. In most cases, data are input while the patient is being cared for. The information is collected and stored together with data automatically received from the dispatch centre. The latter date are transferred by a mobile radio network to the ambulance. Medical date (e.g. electrocardiograms) are transferred from the ambulance over the data network to the receiving medical facility. All transferred data are finally collected in a database for statistical analysis and follow-up.