The invention relates to a method of manufacturing a breast prosthesis having a shell-like body that has a film bag having a filling, wherein the method comprises the following steps: welding and/or adhering plastic films while leaving a region free to form a film bag having a filling passage injecting a flowable filler material through the filling passage into the film bag and welding and/or adhering the plastic films in the region of the filling passage to close the film bag, wherein a flowable sealing compound is injected that comes to lie between the filling passage and the filler material and forms a stopper after the injection of the filler material and before the closing of the film bag.
