A pneumatic tire having improved noise buffering capability and operation stability while maintaining excellent water discharge capability. A circumferential straight main groove (1) is provided at the center of a tread center region. Arc-like curved main grooves (3) where a plurality of arc-like grooves (3a) are circumferentially formed so as to be continuous in a repeated manner are arranged on both sides of the straight main groove (1). Further, circumferential auxiliary grooves (4) with a width smaller than that of any of the straight main groove (1) and arc-like curved main grooves (3) are provided in each of both tread shoulder regions.