Provided is a utility work vehicle including an engine section, a speed changer device and a belt type stepless speed changer device, a rear frame supporting the engine section, and a main frame supporting the rear frame. The rear frame includes right and left rear wheel supporting portions, each of which has a front supporting member and a rear supporting member extending upwards from the rear frame. The rear supporting member disposed on more rear side of the vehicle body than the belt type stepless speed changer device has its upper end connected to a rear frame portion of the main frame. The front supporting member is disposed on more laterally outer side of the vehicle body than the belt type stepless speed changer device. Between an upper end of the front supporting member and the rear frame portion, there is formed a space that allows attachment/detachment of a speed changer cover detachably attached to the belt type stepless speed changer device from a laterally outer side of the vehicle body.