A hydraulic pile driver of the kind having at least one hydraulic cylinder for raising a tup. An arrangement is proposed for allowing the use of oil as the hydraulic fluid. The cylinder has a closed chamber around it, to which oil under pressure is supplied. An apertured cuff around or within the cylinder is moved to bring its apertures periodically into and out of registry with apertures in the cylinder wall to connect the cylinder space alternately with said chamber for supply of fluid to the cylinder and to a discharge line for the discharge of fluid from the cylinder. The volume of the chamber is considerably greater than the volume of the cylinder space. The apertures in the cuff and the cylinder wall that register for discharge of the oil from the cylinder have a total cross-sectional area at least equal to that of the cylinder space to make for fast discharge of the oil, thereby ensuring free fall of the tup.