In a transmission for a working vehicle, a working unit includes a hydraulic power unit and a valve unit enclosed in a first bulging portion of a transmission case closer to an upper side or on a top surface thereof and connected with each other along a vehicle lengthwise direction. The first bulging portion is closer to a first lateral side along the vehicle width direction of the transmission case, while a hydraulic pump is located closer to a second lateral side. Hydraulic fluid is drawn from the transmission case, around a lower side of the hydraulic pump, through a suction port thereof, and discharged to a suction port of the valve unit. The hydraulic power unit includes a cylinder tube and piston, extending in the lengthwise direction, and a support shaft, extending along the width direction, which is supported by the transmission case and connected to a lift arm.