A motorcycle pneumatic tire comprising: a pair of bead portions; a pair of side wall portions continuously extending on the respective bead portions; a tread portion toroidally extending between the side wall portions; and at least one carcass reinforcing the respective portions between the pair of the bead portions, wherein a tire ground-contact surface has a tread pattern that includes plural inclined grooves (21 to 25), a tread width TW is a tire width-direction distance between tread ends TE, which is measured along the tread surface in a state where the tire is fitted to an application rim and inflated to a prescribed internal pressure with no load, and when the tread width TW is equally divided in eight, among the thus equally-divided eight regions (A, B, C and D), a region C constituting a range of 1/4 to 3/8 of the tread width TW on the tire width-direction outer side from the tire equator has the largest number of inclined grooves (21 to 25) included per single pitch of the tread pattern, and characterized in that the tread portion is composed of a central rubber arranged in a tire width-direction central region sandwiching a tire equator and a side rubber arranged in both tire widthwise end portions having a lower modulus than the central rubber and has a structure in which the central rubber and the side rubber are sequentially laminated in both tire widthwise side portions, with the side rubber extending to a tire width-direction inner side further than a point at 1/4 of a tread width TW on a tire width-direction outer side from a tire equator, and the depth of the inclined grooves (21 to 25) is greater than the thickness of the side rubber in at least a part of the region C. a pair of bead portions; a pair of side wall portions continuously extending on the respective bead portions; a tread portion toroidally extending between the side wall portions; and at least one carcass reinforcing the respective portions between the pair of the bead portions, wherein a tire ground-contact surface has a tread pattern that includes plural inclined grooves (21 to 25), a tread width TW is a tire width-direction distance between tread ends TE, which is measured along the tread surface in a state where the tire is fitted to an application rim and inflated to a prescribed internal pressure with no load, and when the tread width TW is equally divided in eight, among the thus equally-divided eight regions (A, B, C and D), a region C constituting a range of 1/4 to 3/8 of the tread width TW on the tire width-direction outer side from the tire equator has the largest number of inclined grooves (21 to 25) included per single pitch of the tread pattern, and characterized in that the tread portion is composed of a central rubber arranged in a tire width-direction central region sandwiching a tire equator and a side rubber arranged in both tire widthwise end portions having a lower modulus than the central rubber and has a structure in which the central rubber and the side rubber are sequentially laminated in both tire widthwise side portions, with the side rubber extending to a tire width-direction inner side further than a point at 1/4 of a tread width TW on a tire width-direction outer side from a tire equator, and the depth of the inclined grooves (21 to 25) is greater than the thickness of the side rubber in at least a part of the region C.