A pneumatic tire is provided which includes a plurality of drainage grooves positioned on each side of a tire equator line that extend at an angle in a direction opposite a rotating direction while curving outward in a tire width direction in a tread portion, with an end of a leading edge closed and an end of a trailing edge open to a tire side. A plurality of sub grooves extending from the drainage grooves in the rotating direction is provided, where an end of the leading edge is closed. The drainage grooves and the sub grooves are arranged so that spacings W1, W2, and W3gradually increase outward in the tire width direction, groove area ratios RA to RE satisfy the relationships |RB−RA|≦9%, RA>RC>RD, and RB>RE, and a groove depth of the drainage grooves in the center region is greater than that in the shoulder portion.