The purpose of this work was to determine the effect of some proces parameters upon tool wear of ball-nose end mills. Tool wear experiments were conducted with an indexable ball-nose end mill, machining blocks of P-20 mold steel at 30 HRC, under conditions similar to those used to produce sculptured surfaces in dies and molds. The investigation focused on the effect of tilt angle and cutting speed on the distribution and progression of tool wear. The computational and experimental procedures developed and demonstrated in this study facilitate the tool wear characterization of ball-nose end mills by reducing a large number of process-related factors to only two chip geometry-related factors.