Provided is a pneumatic tire capable of improving uneven wear resistance and effectively suppressing the occurrence of cracks or defects in the ribs thereof. The pneumatic tire comprises a tread section, a sidewall section, and a bead section. Five main grooves extending in the tire circumferential direction are provided in the tread section, thereby partitioning into six rib columns. A plurality of first sipes are formed in each edge section of a center rib, an intermediate rib, and a shoulder rib. A plurality of first narrow grooves are formed in the center rib and the intermediate rib so as to connect between the main grooves thereof. A plurality of second narrow grooves are formed in the center rib and the intermediate rib so as to connect the first narrow grooves to each other. The interval (Pg1) between the first narrow grooves is 20-60 mm. The interval (Ps1) between the first sipes is 15%-45% of the interval (Pg1) between the first narrow grooves. A ratio (Wa/TDW) between the width (Wa) of the center rib and the development width (TDW) of the tread section is 0.08-0.18, a ratio (Wb/TDW) for the intermediate rib width (Wb) is 0.08-0.18, and a ratio (Wc/Wa) between the shoulder rib width (Wc) and the center rib width (Wa) is 1.20-1.30.