A motorcycle pneumatic tire comprising a plurality of blocks arranged on a tread surface, wherein: when a developed width of the tread surface is divided into six equal parts in a tire width direction, and when two regions closest to a tire equatorial plane are defined as a central region, two regions on tire widthwise outermost sides are respectively defined as shoulder regions, and two regions located between the central region and the shoulder regions are defined as intermediate regions, a plurality of wide blocks, each having a tire widthwise length larger than a tire circumferential length, formed in at least the central region and the intermediate regions, and a plurality of narrow blocks, each having a smaller tire widthwise length than each of the wide blocks, formed in at least the intermediate regions; and in a developed view of the tread surface, the following relations to are satisfied: 1.5 ≤ W 1 / L 1 ≤ 4.0 0.5 ≤ W 2 / L 2 ≤ 1.5 0.3 ≤ S 1 ⁢ M / S 1 ≤ 0.6 and 0.5 ≤ S 2 ⁢ M / S 2 ≤ 1.0 where L1 is the tire circumferential length of each of the wide blocks, W1 is the tire widthwise length of each of the wide blocks, L2 is the tire circumferential length of each of the narrow blocks, W2 is the tire widthwise length of each of the narrow blocks, S1 is the area of the tread surface of each of the wide blocks, S2 is the area of the tread surface of each of the narrow blocks, S1M is the area of the tread surface located in the intermediate regions within the area S1, and S2M is the area of the tread surface located in the intermediate regions within the area S2, and wherein: each wide block is disposed with a narrow block to form a pair at positions in substantially the same phase in a tire circumferential direction, and the wide blocks and the narrow blocks located in substantially the same phase in the tire circumferential direction are located on different tire widthwise half portions divided by the tire equatorial plane. when a developed width of the tread surface is divided into six equal parts in a tire width direction, and when two regions closest to a tire equatorial plane are defined as a central region, two regions on tire widthwise outermost sides are respectively defined as shoulder regions, and two regions located between the central region and the shoulder regions are defined as intermediate regions, a plurality of wide blocks, each having a tire widthwise length larger than a tire circumferential length, formed in at least the central region and the intermediate regions, and a plurality of narrow blocks, each having a smaller tire widthwise length than each of the wide blocks, formed in at least the intermediate regions; and a plurality of wide blocks, each having a tire widthwise length larger than a tire circumferential length, formed in at least the central region and the intermediate regions, and a plurality of narrow blocks, each having a smaller tire widthwise length than each of the wide blocks, formed in at least the intermediate regions; and in a developed view of the tread surface, the following relations to are satisfied: 1.5 ≤ W 1 / L 1 ≤ 4.0 0.5 ≤ W 2 / L 2 ≤ 1.5 0.3 ≤ S 1 ⁢ M / S 1 ≤ 0.6 and 0.5 ≤ S 2 ⁢ M / S 2 ≤ 1.0 where L1 is the tire circumferential length of each of the wide blocks, W1 is the tire widthwise length of each of the wide blocks, L2 is the tire circumferential length of each of the narrow blocks, W2 is the tire widthwise length of each of the narrow blocks, S1 is the area of the tread surface of each of the wide blocks, S2 is the area of the tread surface of each of the narrow blocks, S1M is the area of the tread surface located in the intermediate regions within the area S1, and S2M is the area of the tread surface located in the intermediate regions within the area S2, and wherein: each wide block is disposed with a narrow block to form a pair at positions in substantially the same phase in a tire circumferential direction, and the wide blocks and the narrow blocks located in substantially the same phase in the tire circumferential direction are located on different tire widthwise half portions divided by the tire equatorial plane. each wide block is disposed with a narrow block to form a pair at positions in substantially the same phase in a tire circumferential direction, and the wide blocks and the narrow blocks located in substantially the same phase in the tire circumferential direction are located on different tire widthwise half portions divided by the tire equatorial plane.