Abstract: A sealing assembly for molds used for casting sanitary fixtures including at least one female die which is capable of defining the molding cavity of the item as well as at least one male die which is designed to be introduced into and withdrawn from said molding cavity, and which is provided with a mating surface capable of interacting with an associated mating surface of at least one female die. The sealing assembly includes a tubular elastic body of annular shape which is placed within a peripheral groove recessed in the mating surface of at least one male die, and which is connected to an assembly capable of alternately deflating and inflating said elastic tubular body so that the latter assumes a first transverse shape which is completely accommodated within the corresponding transverse-shape of the groove, and a second transverse shape which projects beyond the mouth of the groove, where it comes to rest against the facing associated mating surface of at least one female die.