Abstract: Simple cleaning, exact dosing and a high degree of operating safety are assured with a dosing device for dispensing a liquid through a liquid dispensing nozzle from a container holding the liquid under pressure in the interior thereof, which comprises a liquid dosing piston displaceable along the axis thereof and housed in a bushing having a screw thread for attachment to the container. The piston has a valve body at an end thereof adjacent the interior of the container and a section of reduced cross section adjoining the valve body, the valve body having a cylindrical surface coaxial with the piston.