A pneumatic tire, comprising: a tread portion extending in a tire circumferential direction (Tc) and having an annular shape; a pair of sidewall portions disposed on both sides of the tread portion; and a pair of bead portions disposed inward of the pair of sidewall portions in a tire radial direction, wherein a carcass layer is mounted between the pair of bead portions, the tread portion has a multilayer structure including a cap tread rubber layer and an undertread rubber layer, grooves (21, 22) and sipes are formed in the tread portion, a snow traction index STI is set to 180 or more, wherein the snow traction index STI is calculated as follows: STI = − 6.8 + 2202 ρ g + 672 ρ s + 7.6 Dg wherein ρg is a ratio between a total length of extending components of the grooves (21, 22) in the tire lateral direction in mm and a total area of a ground contact region in mm 2, ρs is a ratio between a total length of extending components of the sipes in the tire lateral direction in mm and a total area of a ground contact region in mm 2, and Dg: is the average groove depth in mm, a tread radius in a meridian cross-section of the tread portion falls within a range of from 80% to 140% of a tire outer diameter, a ground contact width of the tread portion falls within a range of from 70% to 75% of a tire cross-sectional width, and a height of a bead filler disposed on an outer circumference of a bead core of each of the pair of bead portions is 40% or less of a tire cross-sectional height. a tread portion extending in a tire circumferential direction (Tc) and having an annular shape; a pair of sidewall portions disposed on both sides of the tread portion; and a pair of bead portions disposed inward of the pair of sidewall portions in a tire radial direction, wherein a carcass layer is mounted between the pair of bead portions, the tread portion has a multilayer structure including a cap tread rubber layer and an undertread rubber layer, grooves (21, 22) and sipes are formed in the tread portion, a snow traction index STI is set to 180 or more, wherein the snow traction index STI is calculated as follows: STI = − 6.8 + 2202 ρ g + 672 ρ s + 7.6 Dg wherein ρg is a ratio between a total length of extending components of the grooves (21, 22) in the tire lateral direction in mm and a total area of a ground contact region in mm 2, ρs is a ratio between a total length of extending components of the sipes in the tire lateral direction in mm and a total area of a ground contact region in mm 2, and Dg: is the average groove depth in mm, ρg is a ratio between a total length of extending components of the grooves (21, 22) in the tire lateral direction in mm and a total area of a ground contact region in mm 2, ρs is a ratio between a total length of extending components of the sipes in the tire lateral direction in mm and a total area of a ground contact region in mm 2, and Dg: is the average groove depth in mm, a tread radius in a meridian cross-section of the tread portion falls within a range of from 80% to 140% of a tire outer diameter, a ground contact width of the tread portion falls within a range of from 70% to 75% of a tire cross-sectional width, and a height of a bead filler disposed on an outer circumference of a bead core of each of the pair of bead portions is 40% or less of a tire cross-sectional height.