A pneumatic tire comprising: a tread; a pair of side pieces; a pair of beads; and a carcass, wherein each side piece extends from an edge of the tread substantially inward in a radial direction, each bead is located inward of the side piece in an axial direction at a radially inner portion of the side piece, the carcass extends along inner sides of the tread and the side pieces and on and between the one bead and the other bead, each side piece includes a main body and a rim protector projecting from the main body outward in the axial direction, the rim protector projects from a reference surface of the side piece being an outer surface of the main body outward in the axial direction and has a top which is a position at which a height from the reference surface is maximum, the rim protector extends in a circumferential direction, the rim protector has a first inclined surface extending from the top of the rim protector substantially outward in the radial direction and a second inclined surface extending from the top of the rim protector substantially inward in the radial direction, a profile of the outer surface of the main body is represented by a plurality of circular arcs aligned in the radial direction, these circular arcs include an outer circular arc extending substantially outward in the radial direction from a first reference position corresponding to a position at which the tire without the rim protector has a maximum width in the axial direction, and an inner circular arc extending substantially inward in the radial direction from the first reference position, the outer circular arc and the inner circular arc are tangent to each other at the first reference position, a profile of the first inclined surface is represented by a first circular arc, and a profile of the second inclined surface is represented by a second circular arc, the first circular arc is tangent to the outer circular arc and the second circular arc is tangent to the inner circular arc, and a ratio of a height in the radial direction from a bead base line of the tire to the top relative to a cross-sectional height of the tire is equal to or greater than 0.27 and equal to or less than 0.34, characterized in that a ratio of a thickness of the side piece at the first reference position relative to a thickness of the side piece at the top is equal to or greater than 0.20 and equal to or less than 0.30. a tread; a pair of side pieces; a pair of beads; and a carcass, wherein each side piece extends from an edge of the tread substantially inward in a radial direction, each bead is located inward of the side piece in an axial direction at a radially inner portion of the side piece, the carcass extends along inner sides of the tread and the side pieces and on and between the one bead and the other bead, each side piece includes a main body and a rim protector projecting from the main body outward in the axial direction, the rim protector projects from a reference surface of the side piece being an outer surface of the main body outward in the axial direction and has a top which is a position at which a height from the reference surface is maximum, the rim protector extends in a circumferential direction, the rim protector has a first inclined surface extending from the top of the rim protector substantially outward in the radial direction and a second inclined surface extending from the top of the rim protector substantially inward in the radial direction, a profile of the outer surface of the main body is represented by a plurality of circular arcs aligned in the radial direction, these circular arcs include an outer circular arc extending substantially outward in the radial direction from a first reference position corresponding to a position at which the tire without the rim protector has a maximum width in the axial direction, and an inner circular arc extending substantially inward in the radial direction from the first reference position, the outer circular arc and the inner circular arc are tangent to each other at the first reference position, a profile of the first inclined surface is represented by a first circular arc, and a profile of the second inclined surface is represented by a second circular arc, the first circular arc is tangent to the outer circular arc and the second circular arc is tangent to the inner circular arc, and a ratio of a height in the radial direction from a bead base line of the tire to the top relative to a cross-sectional height of the tire is equal to or greater than 0.27 and equal to or less than 0.34, characterized in that a ratio of a thickness of the side piece at the first reference position relative to a thickness of the side piece at the top is equal to or greater than 0.20 and equal to or less than 0.30.