Abstract: The present invention is directed to an apparatus for assembling a uniform-speed joint having an inner rotary body and an outer rotary body which transmits a rotational force from one to the other through a plurality of small spheres disposed in receiving holes in the outer peripheral surface of the inner rotary body. The apparatus comprises a carrying member for carrying the outer rotary bodies such that the inner surface of the rotary body is oriented upward and guide members, including a first guide wall, a second guide wall and a pusher for pushing an inner rotary body along the first guide wall until it contacts the second guide wall.