A work vehicle includes an engine, an intake passage through which combustion air flows from an ambient air inlet to an engine, an air cleaner for removing dust contained in the combustion air, a throttle valve for adjusting an intake amount of the combustion air by the engine, a blowby gas returning passage for returning blowby gas discharged from the engine to a mid portion of the intake passage, and an inclined passage portion that assumes a progressively downwardly inclined posture to be located at a lower position on downstream side in a flow direction, the inclined passage portion having a water draining portion at its lowermost end.