A bearing device for a wheel has a stem shaft of an outer joint member of a constant-velocity universal joint fit and inserted in a hole of a hub wheel, the stem shaft and hub wheel being coupled through an intermediation of a recess-projection fitting structure. Projections extending in an axial direction are provided on one of the stem shaft and an inner diameter surface of the hole of the hub wheel. The projections are press-fit into another of the stem shaft and the inner diameter surface of the hole along the axial direction. Recesses that adhere to and fit the projections are formed in the other. An end on an inboard side of the hub wheel is caulked to an outer diameter side to form a caulking section and preload is applied to a roller bearing by the caulking section.