A heavy duty tire provided in a tread portion with a pair of center main grooves disposed on both outer sides of the tire equator and extending in a zigzag shape continuously in the tire circumferential direction, and a pair of shoulder main grooves disposed outside the center main grooves in the tire axial direction and extending in a zigzag shape continuously in the tire circumferential direction so that a center land portion between the pair of center main grooves, a pair of middle land portions between the center main grooves and the shoulder main grooves, and a pair of shoulder land portions located outside the shoulder main grooves in the tire axial direction are defined, wherein each center main groove has a first groove edge on the tire equator side and a second groove edge on the tread edge side, each shoulder main groove has a third groove edge on the tire equator side and a fourth groove edge on the tread edge side, and the middle land portion is provided with: a plurality of middle lateral shallow grooves connecting the most tread edge side apex portions of the second groove edge of the center main groove, and the most tire equator side apex portions of the third groove edge of the shoulder main groove, a plurality of first middle lateral sipes extending along the respective middle lateral shallow grooves at the groove bottom of the middle lateral shallow grooves and connecting the shoulder main groove and the center main groove, and a plurality of second middle lateral sipes formed between the circumferentially adjacent middle lateral shallow grooves and connecting the most tire equator side apex portions of the second groove edge of the center main groove and the most tread edge side apex portions of the third groove edge of the shoulder main groove, characterized in that the respective numbers of the middle lateral shallow grooves, the first middle lateral sipes and the second middle lateral sipes provided in one of the middle land portions are 35 to 45, wherein the groove depth of the middle lateral shallow grooves is 10 % to 30 % of the groove depth of the center main grooves. a plurality of middle lateral shallow grooves connecting the most tread edge side apex portions of the second groove edge of the center main groove, and the most tire equator side apex portions of the third groove edge of the shoulder main groove, a plurality of first middle lateral sipes extending along the respective middle lateral shallow grooves at the groove bottom of the middle lateral shallow grooves and connecting the shoulder main groove and the center main groove, and a plurality of second middle lateral sipes formed between the circumferentially adjacent middle lateral shallow grooves and connecting the most tire equator side apex portions of the second groove edge of the center main groove and the most tread edge side apex portions of the third groove edge of the shoulder main groove, characterized in that the respective numbers of the middle lateral shallow grooves, the first middle lateral sipes and the second middle lateral sipes provided in one of the middle land portions are 35 to 45, wherein the groove depth of the middle lateral shallow grooves is 10 % to 30 % of the groove depth of the center main grooves.