Pneumatic tire

A pneumatic tire (1) comprises a tread portion (2) provided with a tread groove (16) and a tread reinforcing band (10); the tread reinforcing band (10) is disposed radially outside a carcass in the tread portion as the radially outermost reinforcing cord layer composed of a plurality of reinforcing cords (11) laid at an angle of not more than 5 degrees with respect to the tire circumferential direction; the reinforcing cords (11) are composed of a plural number N of steel filaments (14) twisted together into a 1XN open twist structure; the shortest distance (L5) between the bottom of the tread groove (16) and the underlying reinforcing cords (11) is in a range of from 0.5 to 2.0 mm.