A work vehicle comprising: a power transmission unit including: a differential device for transmitting power to left and right axles; a power transmission mechanism for transmitting power to the differential device; and a transmission shaft for transmitting power to the power transmission unit; wherein the power transmission mechanism includes: a first gear mechanism to which power is transmitted from the transmission shaft; and a second gear mechanism that transmits power from the first gear mechanism to the differential device, wherein the first gear mechanism includes: a first drive gear to which power is transmitted from the transmission shaft, and a first driven gear rotatable about a rotational axis orthogonal to a rotational axis of the first drive gear and meshing with the first drive gear; and the second gear mechanism includes: a second drive gear rotatable about the same rotational axis as the first driven gear and rotatable with the first driven gear; and a second driven gear rotatable about a rotational axis parallel with the rotational axis of the second drive gear and meshing with the second drive gear, and wherein the power transmission unit includes a case which accommodates the differential device and the power transmission mechanism; and characterized in that the power transmission mechanism includes an input shaft provided to protrude rearwards from a rear portion of the case and supporting the first drive gear, the input shaft being disposed downwardly of the axle with respect to a work vehicle up/down direction. a power transmission unit including: a differential device for transmitting power to left and right axles; a power transmission mechanism for transmitting power to the differential device; and a differential device for transmitting power to left and right axles; a power transmission mechanism for transmitting power to the differential device; and a transmission shaft for transmitting power to the power transmission unit; wherein the power transmission mechanism includes: a first gear mechanism to which power is transmitted from the transmission shaft; and a second gear mechanism that transmits power from the first gear mechanism to the differential device, a first gear mechanism to which power is transmitted from the transmission shaft; and a second gear mechanism that transmits power from the first gear mechanism to the differential device, wherein the first gear mechanism includes: a first drive gear to which power is transmitted from the transmission shaft, and a first driven gear rotatable about a rotational axis orthogonal to a rotational axis of the first drive gear and meshing with the first drive gear; and a first drive gear to which power is transmitted from the transmission shaft, and a first driven gear rotatable about a rotational axis orthogonal to a rotational axis of the first drive gear and meshing with the first drive gear; and the second gear mechanism includes: a second drive gear rotatable about the same rotational axis as the first driven gear and rotatable with the first driven gear; and a second driven gear rotatable about a rotational axis parallel with the rotational axis of the second drive gear and meshing with the second drive gear, and a second drive gear rotatable about the same rotational axis as the first driven gear and rotatable with the first driven gear; and a second driven gear rotatable about a rotational axis parallel with the rotational axis of the second drive gear and meshing with the second drive gear, and wherein the power transmission unit includes a case which accommodates the differential device and the power transmission mechanism; and characterized in that the power transmission mechanism includes an input shaft provided to protrude rearwards from a rear portion of the case and supporting the first drive gear, the input shaft being disposed downwardly of the axle with respect to a work vehicle up/down direction.