Device for filling an aerosol container with a liquid using in particular a filling arrangement equipped with a pusher element (12), includes a cup designed to accommodate the liquid for filling the aerosol container, this cup being provided on its bottom with an injection opening adapted to the valve of the aerosol container, a piston head (7) acting by pushing on the filling liquid contained in the cup for transferring it from the cup to the container. The piston head (7) comes in the form of a scraper in continuous contact with the inside wall of the cup during the transfer operation. The piston head (7) is shaped to work with the cup after transfer to keep the piston head (7) within the cup to form an airtight wall that retains the residual liquid that has not been transferred within the cup.