A pneumatic tire comprising a tread portion provided with a pair of crown main grooves disposed one on each side of the tire equator, and extending continuously in the tire circumferential direction, a plurality of center axial grooves connecting between the pair of crown main grooves, and a plurality of center blocks divided by the pair of crown main grooves and the center axial grooves, wherein the center blocks include a siped center block, the siped center block has a first block side wall and a second block side wall respectively extending along the pair of crown main grooves, and is provided with a first sipe extending from the first block side wall to the second block side wall, in the top view of the siped block, the first block side wall and the second block side wall are substantially v-shaped to have a vertex (27a, 27b) protruding outwardly of the block, and the first sipe has a wavy configuration at least partially of its length, and one end in the tire axial direction of the first sipe is positioned on one side in the tire circumferential direction of the vertex of the first block side wall, whereas the other end in the tire axial direction of the first sipe is positioned on the other side in the tire circumferential direction of the vertex of the second block side wall, characterized in that the first sipe comprises a first portion including one end, a second portion including the other end, and a third portion between the first portion and the second portion, each of the first portion and the second portion has a wavy configuration extending in the tire axial direction while oscillating in the tire circumferential direction, the first portion is disposed in a different position in the tire circumferential direction than the second portion, the third portion extends straight while inclining with respect to the tire axial direction, each of the first block side wall and the second block side wall is provided with a slot denting in the tire axial direction, and said one end and the other end of the first sipe are connected to the respective slots. a tread portion provided with a pair of crown main grooves disposed one on each side of the tire equator, and extending continuously in the tire circumferential direction, a plurality of center axial grooves connecting between the pair of crown main grooves, and a plurality of center blocks divided by the pair of crown main grooves and the center axial grooves, wherein the center blocks include a siped center block, the siped center block has a first block side wall and a second block side wall respectively extending along the pair of crown main grooves, and is provided with a first sipe extending from the first block side wall to the second block side wall, in the top view of the siped block, the first block side wall and the second block side wall are substantially v-shaped to have a vertex (27a, 27b) protruding outwardly of the block, and the first sipe has a wavy configuration at least partially of its length, and one end in the tire axial direction of the first sipe is positioned on one side in the tire circumferential direction of the vertex of the first block side wall, whereas the other end in the tire axial direction of the first sipe is positioned on the other side in the tire circumferential direction of the vertex of the second block side wall, characterized in that the first sipe comprises a first portion including one end, a second portion including the other end, and a third portion between the first portion and the second portion, each of the first portion and the second portion has a wavy configuration extending in the tire axial direction while oscillating in the tire circumferential direction, the first portion is disposed in a different position in the tire circumferential direction than the second portion, the third portion extends straight while inclining with respect to the tire axial direction, each of the first block side wall and the second block side wall is provided with a slot denting in the tire axial direction, and said one end and the other end of the first sipe are connected to the respective slots.