This study developed, and applied, a portable emergency medical information system, enabling patient-related information to be efficiently shared with the hospital information system, via a PDA, while an emergency patient was being taken to the emergency room. The system consisted of an emergency patient`s server for monitoring the condition of the emergency patients registered in an emergency room, in real time, and a PDA terminal that delivers patient and emergency ac tivity information to a se rver through a wireless connection. Within the emergency room of G hospital a DB server was in charge of the stored information to de liver information the patients' conditions, emergency treatments, and activities, with 119 emergency medical system personnel being responsible for the information storage space, via a PDA. In addition, the member of personnel in charge of an emergency room can check the registrations of the 119 EMS personnel through a user's application, that enablings real-time checks of the fir st-aid patients being registerted in the information storage space. In conclusion, the development and experimental application of the emergency patient information delivery system demonstrated that a PDA can be used in an emergency medical environment. Modification to the interface, for a convenient input into a PDA, and an increase in its usability, through the training and continuous studies of the users, will help to make qualitative improvements to this emergency medical service.