A vehicle wheel bearing has a sealing device (12) on an inboard side of the bearing with a first sealing plate (23) mounted on an inner ring (3), and a second sealing plate (24) mounted on an outer member (10), arranged opposite to the first sealing plate (23). The first sealing plate (23) has a radially extending portion arranged on the inboard side of the bearing. An encoder (25) is bonded on the radially extending portion. The encoder (25) is made of elastomer material which includes magnetic substance powder. The N and S poles are alternately magnetized along the circumferential direction. The second sealing plate (24) has a substantially "L"-shaped cross-section formed by a cylindrical portion and a radially extending portion. Integral side-lip(s) slidingly contact the radially extending portion of the first sealing plate (23). A protecting cover (27) is mounted on the first sealing plate (23) so that it intimately contacts with the encoder (25).