A wheel support bearing assembly including an outer member having an inner periphery formed with a plurality of raceway surfaces; an inner member having an outer periphery formed with raceway surfaces cooperable and aligned with the raceways in the outer member; rows of balls interposed between the raceway surfaces in the outer member and the raceway surfaces in the inner member, respectively; and a wheel fitting flange provided in the outer periphery of one of the outer and inner members. In the wheel support bearing assembly, the diameter of the pitch circle depicted by the balls of a row on an outboard side is greater than the pitch circle of the balls of the row on an inboard side, and the ratio of the diameter of the balls relative to the pitch circle diameter of the row of the balls on the inboard side is within the range of 0.14 to 0.25.