A pneumatic tire comprising: a tread portion provided on each side of the tire equator with a crown main groove and a shoulder main groove both extending circumferentially of the tire to axially divide the tread portion into a center land portion, a pair of middle land portions and a pair of shoulder land portions (30, 40), the crown main groove and the shoulder main groove each having a zigzag configuration having axially inward vertices and axially outward vertices alternating in the tire circumferential direction, characterized by central axial grooves extending from the inward vertices of one of the crown main grooves to the inward vertices of the other crown main groove to divide the center land portion into center blocks, the center blocks each provided with two parallel center sipes extending between the crown main grooves to form a central part of the center block therebetween, wherein the maximum axial width of the center block occurs in the central part, middle axial grooves extending from the outward vertices of said crown main groove to the outward vertices of said shoulder main groove to divide the middle land portion therebetween into middle blocks, said middle axial grooves inclined with respect to the tire axial direction and including first middle axial grooves and second middle axial grooves alternately arranged in the tire circumferential direction, wherein the first middle axial grooves are inclined to one circumferential direction whereas the second middle axial grooves are inclined to the other circumferential direction, and the middle blocks each provided with middle sipes extending from said crown main groove to said shoulder main groove and inclined with respect to the tire axial direction, wherein the middle sipes in each middle block include a first middle sipe disposed on the first middle axial groove side and inclined to the same circumferential direction as the first middle axial groove, and a second middle sipe disposed on the second middle axial groove side and inclined to the same circumferential direction as the second middle axial groove. a tread portion provided on each side of the tire equator with a crown main groove and a shoulder main groove both extending circumferentially of the tire to axially divide the tread portion into a center land portion, a pair of middle land portions and a pair of shoulder land portions (30, 40), the crown main groove and the shoulder main groove each having a zigzag configuration having axially inward vertices and axially outward vertices alternating in the tire circumferential direction, characterized by central axial grooves extending from the inward vertices of one of the crown main grooves to the inward vertices of the other crown main groove to divide the center land portion into center blocks, the center blocks each provided with two parallel center sipes extending between the crown main grooves to form a central part of the center block therebetween, wherein the maximum axial width of the center block occurs in the central part, middle axial grooves extending from the outward vertices of said crown main groove to the outward vertices of said shoulder main groove to divide the middle land portion therebetween into middle blocks, said middle axial grooves inclined with respect to the tire axial direction and including first middle axial grooves and second middle axial grooves alternately arranged in the tire circumferential direction, wherein the first middle axial grooves are inclined to one circumferential direction whereas the second middle axial grooves are inclined to the other circumferential direction, and the middle blocks each provided with middle sipes extending from said crown main groove to said shoulder main groove and inclined with respect to the tire axial direction, wherein the middle sipes in each middle block include a first middle sipe disposed on the first middle axial groove side and inclined to the same circumferential direction as the first middle axial groove, and a second middle sipe disposed on the second middle axial groove side and inclined to the same circumferential direction as the second middle axial groove.