In a lubricant dosing arrangement for the lubrication of valve shafts on the cylinder heads of piston engine wherein the valve shafts are axially movably supported in housing bores formed in the cylinder heads and the housing bores include spaced lubricant seals so as to form between the seals around the valve shaft lubricant reservoirs, means are provided for supplying lubricant to the lubricant reservoirs and the valves shafts include means for permitting passage of lubricant out of the reservoir at a rate depending on the lift movement of the valve shafts so as to dose the lubricant volume permitted to flow out of the lubricant reservoir for the lubrication of the valve shaft.