To provide a pneumatic tire mounted to a wheel having a large rim flange on one side and enabling exploratory traveling when tire internal pressure is lowered.

This pneumatic tire 1 is mounted to the wheel 10 in which the height H of one rim flange (hereinafter referred to as the large rim flange) 11 with a rim diameter R made as a reference is larger than the height H of the other side (hereinafter referred to as a small rim flange) 12. The tire 1 has a projecting part 61 formed on a side wall located on the large rim flange 11 side and engaged with the large rim flange 11 when tire air pressure is lowered in the rim assembled state of the tire 1 and a reinforcing layer 63 for reinforcing the rigidity of the side wall located on the small rim flange 12 side.