The radio frequency identification (RFID) technology promises to leverage eHealth systems. Highly pervasive RFID enables remote identification, tracking, and localization of the medical staff, patients, drugs, and equipment thus increasing safety, optimizing in real-time management, and providing support for new ambient-intelligent services. This article presents the potential and challenges on the use of RFID in healthcare. First, we state the required RFID infrastructure and its impact on patient life cycle. Then, based on this description, we identify and discuss not only the issues of large deployments, such as privacy, localization, and interference with medical devices, but also middleware systems to integrate this technology within multimedia and body area networks. Finally, we picture the future RFID-equipped hospital room, where RFID is the basis of the eHealth system.