Radio-frequency identification (RFID) technology is being used increasingly for its efficiency and safety. The goal of this study is to evaluate the RFID technology within a hospital information system (HIS) for better workflow management in a health promotion center. We developed an RFID (433 mHz) real-time tracking system to monitor patients at the room level. Then we implemented an automatic workflow management by integrating RFID system with HIS. If a patient has finished one examination, the next step is determined automatically by previous number of examined patients and duration in each examination room. We performed interrupted time-series analysis of the mean waiting time for patients in a health promotion center compared with a control group of outpatients in the hospital's radiology department before and after the implementation of an RFID-based system. After implementation of the RFID system, the mean waiting time of patients in the health promotion center decreased significantly (from 5.4 to 4.3 min, 20% decrease) compared with the control group (from 3.8 to 3.5 min, 8% decrease). The RFID system integrated with HIS increases workflow efficiency by shortening the mean waiting time during the workflow process and provides valuable real-time data for physicians and staff regarding workflow efficiency.