In recent years, the number of elderly people living alone has grown rapidly. This increases the need for indoor healthcare services that help elderly residents live a safe and independent life. There has been increasing interest in indoor ubiquitous healthcare (U-Healthcare) applications that monitor the elderly unobtrusively via sensors and that warn them or healthcare providers of abnormal conditions. In U-Healthcare applications, automatically locating and tracking users who move around a building is a fundamental feature. Outdoor location sensing technologies such as the global positioning systems are not suitable for use in indoor environments, such as "smart home" applications, because their indoor-based location sensing lacks accuracy. This paper proposes an indoor U-Healthcare system that uses radio-frequency identification technology to accurately locate and track the elderly. The proposed system provides real-time monitoring of elderly people’s whereabouts. In addition, it analyzes their locations in association with time slots and the length of time they stay in the same place, thus inferring information such as movement patterns, ranges, and frequencies. This information is used to determine elderly people's wellbeing and to warn family or healthcare workers of any potential problems. The proposed indoor U-Healthcare system improves the quality and convenience of care delivered to elderly people.