Abstract: A tire condition monitoring apparatus for use in a vehicle. The apparatus includes an initiator arranged on a nonmetallic mudguard of the vehicle. The initiator transmits a trigger signal. A transmitter is arranged in the tire and includes a sensor for detecting the condition of the tire. A trigger signal detection circuit receives the trigger signal. A transmission circuit transmits information related with the tire condition when the detection circuit receives the trigger signal. A receiver is arranged on a body frame of the vehicle. The receiver includes a reception circuit for receiving the information from the transmitter and a controller for controlling the transmission of the trigger signal from the initiator.