A tire monitoring apparatus for a vehicle has plural transmitters arranged in plural tires for detecting air pressure of the corresponding tire and transmitting information including a detecting result by a radio wave, plural receivers for receiving the information transmitted from the respective transmitters, and signal receiving sensitivity changing means for changing signal receiving sensitivities. In the apparatus, each of the receivers is arranged in such a manner that a distance between one receiver and its corresponding transmitter is made shorter than the other distances between the one receiver and the other transmitters. A control means controls the signal receiving sensitivity changing means such that each of the receivers receives only the information included in the radio wave, which has a largest signal receiving level among the radio waves transmitted from the plural transmitters.