An apparatus for protecting a user's knee or other joint which comprises two generally semi-cylindrical rigid members each having semi-hemispherical overlapping portions and hingedly connected to allow a movement of the joint. Additional features of the protector include a replaceable inner pad, easily releasable and reusable hinges which provide the only attachment means for inner padding of the protector, replaceable outer attachment strips which may be made of varying materials which provide different adhesion properties, slightly elastic straps, and an attachment clip which adjustably attaches to one end of a strap and securely and releaseably attaches to a buckle located on a side edge of the rigid semi-cylindrical member.