A heavy duty tire comprises a belt disposed radially outside a carcass in the tread portion, and a belt cushion rubber layer inserted between the carcass and each axial edge portion of the belt. The complex elastic modulus of the belt cushion rubber layer is in a range of from 3.5 to 4.5 MPa. The belt is made up of three plies each made of parallel steel cords inclined at an angle of from 15 to 23 degrees with respect to the tire equator. With respect to the tire equator, the inclination of the belt cords of the radially innermost first ply is opposite to that of the middle second belt ply. The second belt ply is narrower than the first belt ply and wider than the radially outermost third belt ply. The ply strengths S1, S2 and S3 of the first, second and third belt plies, respectively, satisfy: (1) S1>S2, (2) S1>S3, (3) 55≦S1≦75, and (4) 1.25≦S1/S2≦1.65.