A wheel bearing device to ensure a sufficient durability and life even with the application of bending moment acting on the wheel bearing device. An outer joint member of a constant velocity joint is fitted into the inside of a wheel hub and a portion thereof is swaged radially outward by plastic deformation to unite the wheel hub and the outer joint member. The outer joint member includes a pilot part adjacent the plastically deformed portion, and the ratio of an inside diameter nulld2 of the pilot part to an inside diameter nulld1 of the plastically deformed portion is set 1.110 or less.