Abstract: In a pneumatic tire for a motorcycle where grooves 30, 31 (inclined portion 32) extending generally in a width direction are formed on an outer surface of a tread portion 13 and a rotational direction is designated, driving performance or braking performance is improved. Driving force affects on a tire for a rear wheel during accelerated running, so that an entire land portion 35 between the inclined portions 32 is about to lean backwardly in the rotational direction. However, the inclined portion 32 is generally inclined forwardly in the rotational direction from a deepest point D toward an opening end K, so that a support portion 36 formed at a rear end of each land portion 35 in the rotational direction and having a substantially triangular shape strongly resists the leaning, thereby effectively suppressing the leaning of each land portion 35. As a result, grip force during driving is improved, thereby improving driving performance.