In a tire inflation pressure detection device, a receiver functions such that, when an ignition switch is on, power is generated by a power supply controller to set the power supply state of the receiver to one in which frame reception is enabled to detect the inflation pressure of a tire, and such that, when the IG is off, in each predetermined intermittent cycle power is generated by the power supply controller to set the power supply state of the receiver to one in which frame reception is enabled to detect the inflation pressure of the tire. A transmitter determines whether a decrease in tire inflation pressure occurs, and when the decrease occurs, the transmitter transmits frames more frequently than before the occurrence of the decrease in tire inflation pressure at a shorter frame transmission time interval than a regular transmission cycle during a high-frequency transmission period.