Abstract: A method for forming a grommet element including two successive steps which are performed on an assembly of conduits, such as cables or wires. The first step consists of sealing the conduit assembly under pressure, while the second step involves molding PVC or another thermoplastic elastomer over the sealed structure to form the grommet. A mold is also provided for carrying out the method. The mold includes a stationary portion and an axially movable portion.