The invention relates to a method and system for monitoring room activity. A tray sensing device detects the presence of a tray in a given location and forwards the information to a tray controller. The tray can be a conventional tray for supporting food articles or can be supported or integral with a food cart. The system also includes monitoring door lock and door tag information. Information from the tray sensing device, door lock/tag controller and is received at a room controller. The room controller of each room can include a wireless network to the tray controller, door lock/tag controller. The room controller can also monitor information of the room such as, for example, temperature information and light intensity information, and receive information regarding room activities, such as, for example, room service ordering, housekeeping minibar and checkout routine. Information from the room controller can be forwarded to a central information system. The central information system can display the information or activate an alarm. The alarm can be an audio or visual alert. The alarm can be deactivated upon removal of the tray from the given location or upon dispatching of personnel to the given location.