Abstract: A tractor driven stump grinder for a wheeled tractor frame having a drive motor operating the wheels to move the tractor forwardly and rearwardly, the tractor having a support member movable vertically on the tractor frame and rotatably carrying a generally vertically disposed broadsidely oriented grinder disc. A series of circumferentially spaced generally radial stump grinding tools project peripherally from each vertical face of the grinder disc, and a drive mechanism is provided for rotating the grinder disc in a plane transverse to the longitudinal tractor frame as it cuts a horizontal swath and then a subjacent swath in a pass across the upper end of a stump in both forward and rearward directions of movement of the tractor.