Abstract: The present invention pertains A cooling system for a gas engine piston, the system comprising a cooling oil supply configured to feed a cooling oil flow to the gas engine piston, and a control device configured to control the cooling oil flow based at least on a predetermined parameter. The present invention further pertains to a gas engine comprising at least one gas engine piston and a cooling system according to any of the previous claims, wherein the gas engine piston is configured to be operable with at least one combustion gas. In addition, the present disclosure pertains to a cooling method for a gas engine piston, comprising the steps of receiving at least one predetermined parameter at the control device; controlling the cooling oil flow based on at least the predetermined parameter; and observing a sufficient cooling oil flow fed to the gas engine piston.