A tire/wheel assembly, wherein a run-flat support body (3), comprising an annular shell (4) having an outer peripheral side as a support surface and an inner peripheral side formed in fork-shaped open legs and elastic rings (5) supporting the ends of the legs on a rim, is inserted into a hollow part of a pneumatic tire (2), and wherein the height (A) of the run-flat support body (3) in the cross section thereof is 50 to 60% of the height (SH) of the pneumatic tire (2) in the cross section thereof, and wherein the cross sectional area of the bead cores (7) of the pneumatic tire (2) is 25 to 40 mm2.