A pneumatic tire has a tread portion curved so that the maximum section width of the tire lies between tread edges. The tread portion is provided with central blocks arranged circumferentially of the tire at pitches P1, axially outer blocks arranged circumferentially of the tire at pitches P3, and middle blocks arranged circumferentially of the tire at pitches P2 between the central blocks and axially outer blocks: the pitches P1 have a longer length than the pitches P2 and the central blocks, and the middle blocks are substantially aligned every two or more (number n) pitches P1; two or more circumferential positions at which the central blocks and the middle blocks are substantially aligned are provided around the tire; circumferential positions of the axially outer blocks are between the middle blocks.