Provided is a heavy duty pneumatic tire that includes a tread portion including, in a tread pattern: shoulder lug grooves extending outward in the tire width direction and opening at ground contact edges; a pair of circumferential primary grooves; center lug grooves; center blocks defined by the center lug grooves and the pair of circumferential primary grooves and aligned in the tire circumferential direction; and circumferential secondary grooves extending in the tire circumferential direction in the center block regions and opening to the center lug grooves adjoining the center blocks. The circumferential secondary grooves extend in the tire circumferential direction while changing positions in the tire width direction and each include third groove turning portions formed into a bent shape or a curved shape. The ratio P4/P1 of the width P4 of the circumferential secondary grooves to the width P1 of the circumferential primary grooves is from 0.70 to 1.10.