A work vehicle includes a vehicle body frame extending in the fore/aft direction, the vehicle body frame including a front frame and a rear frame disposed rearwardly of the front frame, a passenger's section provided on the vehicle body frame, a driver's seat disposed on the front side of the passenger's section, and a drive unit including an engine, the drive unit being disposed downwardly of the rear frame. A rear portion of a rear seat disposing space provided rearwardly of the driver's seat is overlapped with an upper side of the rear frame. A rear seat disposed in the rear seat disposing space is selectable in its posture between a first posture where the upper side of the rear frame is opened up to allow visual inspection of the drive unit and a second posture where the rear seat is positioned on the upper side of the rear frame to cover the drive unit.