Abstract: An adjustable roller assembly for sliding doors including a housing adapted to be snap-fit into a recess provided in the upper or lower surface of a door frame, the housing defining a cavity which is open at the lower end. A roller carrier is mounted in the housing cavity and is vertically biased outwardly by one or more coil springs. Rotatably mounted within the roller carrier is a roller adopted to travel along a track. A base plate is disposed within the housing and is connected to a rack member. The rack member is provided with teeth which engage and cooperate with the gear teeth of an adjustment gear extending laterally through both sides of the housing. An engagement slot, adapted to receive a screwdriver or similar tool, is provided in at least one end of the adjustment gear. Vertical adjustment of the base plate may be achieved by rotating the adjustment gear, which vertically moves the rack member and its connected base plate.