Radio Frequency Identification (RFID) is an automatic identification method, relying on storing and remotely retrieving data using RFID tags or transponders. Unlike a Barcode system, RFID can recognize many tags at the same time quickly since RFID tags do not need to be physically read. A RFID system consists of three parts: a tag, a reader and applications (middle ware and server); and it is connected to a wire/wireless communication network. RFID is more effective than a Barcode system in tracking because its unique features, such as distance of reading, durability, recycling, and storage capability. RFID has been applied to various industries for system automation. Recently, medical and healthcare industries started to adopt and apply RFID technology and related applications, which is known as “ubiquitous health,” simply “U-Health.” As an example, if an active tag is attached to a patient with cancer or suffering from dementia, it is easy to track and trace their movements and location within a health care facility. It makes easier to detect a person's bio-signals automatically by connecting an RFID tag to various sensors. These RFID systems thus allow for remote tracking, monitoring and managing a patient's disease. The Samsung Economic Research Institute (2007) in South Korea introduced U-Health service and divided it into several categories according to service characteristics. The first group is the U-Hospital service group, which is to improve the hospital's efficiency; the second group is for home and mobile healthcare services, which helps older people and/or people with chronic diseases using mobile devices; finally, the third group is for wellness services, which focuses on health management and improvement. RFID technology has also great application potential in other fields, including physical activity, physical education and healthcare, e.g., automatic body signal detecting system, patient tracking systems in hospitals, and automatic evaluation system for physical fitness assessment. After an introduction to RFID, key application components and procedures, along with successful application examples, will be described in detail. Application potential in physical activity and fitness testing and tracking will also be reviewed in detail. Finally, the future technical trend of RFID and research needs/directions will be discussed.Keyword(s): exercise/fitness/physical activity, health promotion, technology