Abstract: The smart home paradigm is a promising new trend of research aiming to propose an alternative to postpone the institutionalization of cognitively-impaired silver-aged people. These habitats are intended to provide security, guidance and direct support services to its resident. To be able to fulfill this important mission, a smart home system first has to identify the ongoing activities of its user by tracking, in real time, the position of the main daily living objects. Many researchers addressed this issue by proposing systems based on ultrasonic wave sensors, video cameras, and radio-frequency identification (RFID). However, because of its robustness and its low price, RFID constitutes the most viable technology for smart homes. Recently, several RFID localization algorithms have been developed, mainly for commercial and industrial uses, but they are not precise enough to be used in an assistive recognition context or they focus on active tags, which need batteries and are much more expensive. We present, in this paper, a new algorithmic approach for passive RFID localization in smart homes based on elliptical trilateration and fuzzy logic. This new algorithm has been implemented in a real smart home infrastructure and has been rigorously tested. We also analyze and compare the obtained results with the main existing approaches.