An improvement in a work vehicle having an exhaust gas treatment unit is disclosed. An engine is disposed in an engine room formed in a vehicle body and supported by the vehicle body. A support unit includes right and left vertical struts mounted on the vehicle body across the engine along a vehicle body transverse direction. The exhaust gas treatment unit is disposed inside the engine room and attached to the support unit upwardly of the engine, under a posture elongate along the vehicle body transverse direction.