A constant-velocity universal joint (1, 31, 61) provided with an outside joint member (2, 32, 62), an inside joint member (3, 33, 63) arranged within the outside joint member (2, 32, 62), and a torque-transmitting member (4, 34, 64); a track groove (7, 9, 37, 39, 66) in which a rolling surface of the torque- transmitting member (4, 34, 64) engages being formed on the outside joint member (2, 32, 62) and/or the inside joint member (3, 33, 63), wherein the constant velocity universal joint is characterized in that at least one of the structural members of the constant velocity universal joint (1, 31, 61) comprises a metallic sintered body, the relative density of the metallic sintered body is equal to or greater than 80% and less than 100%, a layer hardened by heat treatment is formed on the surface of the metallic sintered body, and annular structural members comprising a metallic sintered body are subjected to cold-rolling.