This paper presents a guideline-driven healthcare service platform for smart homes. The clinical guidelines are usually established by medical experts according to the symptoms of diseases. Based on the biological and ambient information detected by sensors, the guideline-driven system makes the appropriate care decisions and then takes actions. In case of emergency, the platform uses the short message system to inform the relevant units immediately. The proposed service platform can therefore reduce the burdens of care and unexpected events in an effective way; therefore it enhances the quality of family care.