A tire/wheel assembly in which a run-flat support member 3 is inserted into a cavity of a pneumatic tire 2, where the run-flat support member 3 includes a circular shell 4 in which the outer circumferential side thereof is used as a support surface and the inner circumferential side thereof is opened to have two leg portions, and elastic rings 5 supporting the ends of the two leg portions on a rim. An air path 7 is provided in the elastic ring 5 so as to interconnect the inside and outside of the run-flat support member 3.