This paper presents an application example for the modelling of a mold used for the gas-assisted injection molding process. The simulation software used allows the computation of the distribution of the thickness-fraction of skin material all over the part depending on the process conditions. The illustrations are shown in connection with an industrial mold and the simulation results are compared with experimental data showing a reasonable agreement. The influence of variations of different operation point parameters is shown. Some effects occurring due to the gas flow into the cavity are described.