A central differential for a four-wheel drive motor vehicle is provided on a pair of axles for right and left drive wheels. The differential has a cylindrical differential case connected to a final gear of a transmission, a pair of carriers provided in the differential case one of which is connected to the drive wheels and the other carrier is operatively connected to the other drive wheels. A pair of annular side gears are securely provided in the differential case, and an annular center gear rotatably mounted in the differential case between the side gears. A pair of planetary gears are rotatably supported in the corresponding carrier. Each planetary gear comprises a pair of planet pinions, one of which is engaged with the side gear and the other is engaged with the center gear.