This article presents an analysis of the effect of cavitation on the erosion of pressure moulds intended for the HPDC casting mould manufacturing process. Changes in the surface area of the eroded areas were investigated via photographs of castings at the begin-ning of the mould life as well as at 30%. The individual process variables were described and their influence verified via the cavitation potential module of the Flow3D simulation programme. The results are presented graphically with a description of the relationships and observations. The summary provides an explanation of the results and the dependencies that occurred.