Abstract: A mobile floor grinding vehicle for grinding a floor to a predetermined level and provided with one or more grinding heads which can be continuously adjusted as the vehicle is moved over a floor to maintain the grinding surface of the heads at a fixed position corresponding to the contour to be ground in the floor. Positional control of the heads is effected either by a laser beam from a laser source positioned remote from the vehicle and providing a datum level against which the operative position of the grinding heads is continuously monitored and adjusted using laser beam responsive sensors, or by means of signals generated by an on-board computer which vary in accordance with the initial contours of the floor measured against its desired contours and pre-programmed into the computer.