This study develops a real-time traffic information-based emergency medical service (RTIEMS) system by employing sensor devices, webcam, 2.4 GHz ISM band RF module, ZigBee, GPS, Google Maps, and WiMAX mobile network. In the ambulance, patient biosignals consisting of electrocardiogram (ECG), temperature, oxygen, and pulse can be wirelessly transmitted to the in-car gateway. Then, together with patient real-time video, those biosignals are transmitted via WiMAX mobile network to the server located in the hospital emergency room for immediate first-aid preparation. Furthermore, to avoid jam-packed areas, a traffic guiding subsystem is presented based on the WebGIS that consists of Google Maps and GPS to help patient be delivered to the hospital with shortest time. Experimental results verify the effectiveness of the proposed RTIEMS system in lengthening the golden rescue time; thus significantly enhancing service quality of emergency medical system.