Provided is a motorcycle pneumatic tire in which the wet grip performance is improved while the steering stability during turning is ensured. The motorcycle pneumatic tire includes, on its ground-contact surface: a first inclined groove (21) that extends on a tire width-direction outer side from the vicinity of a tire equator and is inclined in the same direction as a tire rotation direction; and a short groove (22) that is arranged on the extension of a tire width-direction outer end of the first inclined groove (21). The tire width-direction outer end of the first inclined groove is positioned in the vicinity of a point at ¼ of a tread width (TW) from the tire equator on the tire width-direction outer side, while a tire width-direction inner end of the short groove is positioned in a range of ¼ to 5/16 of the tread width (TW) from the tire equator on the tire width-direction outer side; an inclination angle of the first inclined groove with respect to a tire circumferential direction increases toward the tire width-direction outer side; and an angle θA formed by a groove wall of the tire width-direction outer end of the first inclined groove with respect to the direction perpendicular to the tire surface, and an angle θB formed by a groove wall of the tire width-direction inner end of the short groove with respect to the direction perpendicular to the tire surface, satisfy a relationship of θA>θB.