A pneumatic tire comprises a tread portion with a tread surface; four main grooves in the tread surface of the tread portion, extending in a tire circumferential direction; and a center land portion, middle land portions adjacent to the center land portion on either side in a tire lateral direction, and shoulder land portions outwardly adjacent to the middle land portions in the tire lateral direction formed by the main grooves. The main grooves have a wave-like shape with a constant groove width in the tire circumferential direction and with periodic oscillation.