A wheel position detecting apparatus comprises transmitters, a triggering device, and a receiver. The transmitters are attached to the plurality of wheels respectively. Each transmitter transmits a frame responsively to a triggering signal from the triggering device. The frame includes data indicating a reception intensity of the triggering signal. The triggering device is disposed in a vehicle body and outputs the triggering signal toward the transmitters attached to the plurality of wheels. This triggering device is poisoned nearest to a specified wheel among the plurality of wheels to which the triggering signal is outputted, the specified wheel being influenced most heavily by noise generated in the vehicle. The receiver, disposed to the vehicle body, receives the frame and uses the data indicating the reception intensity of the triggering signal to detect positions of the wheels by determining which transmitter is attached to which wheel.