In the busy and crowded environment of health care, accurate location information of mobile medical devices and personnel (e.g. patients or physicians) is often a major challenge. In this paper, we present a real-time asset tracking system deployed within a hospital clinic setting, which tracked a set of mobile assets using small WiFi tags. The deployed system utilized radio signals received from wireless access points to estimate location of tagged assets. The system performed with resolution of within 1.5 meters, which is an acceptable range in such an environment. We developed a web-based graphical interface and a data management system which was capable of tracking and reporting status of an asset and providing an alert signal when it moved out of a designated area. Additionally, detailed logs of asset tracking information were available for archival purposes. This deployment demonstrates the feasibility of a Wi-Fi based positioning system in dynamic medical environments.