A pneumatic tire comprises a tread portion 2 provided with at least one circumferentially continuously extending main groove 3. The main groove 3 has a zigzag periodical pattern formed by circumferentially repeatedly arranging a first oblique segment 11 and a second oblique segment 12 as a repeating unit which define one zigzag pitch. The first oblique segment 11 extends without being bent, and the second oblique segment 12 extends in a bent manner.