In pocket milling which is often encountered in plastic mould manufacture, the demand is to narrow the interval between the surface roughness values obtained at finish milling and the surface roughness values will be met by further finishing operations as far as possible. The implementation and selection of cutting path strategies with appropriate cutting parameters have significant effect on surface roughness. The effect of every single variable on surface roughness is known, however, what kind of results is revealed in their combinations cannot be clearly estimated. The aim of this study is, first, to investigate optimum cutting characteristics of DIN 1.2738 mould steel using high-speed steel end mills. The cutting parameters considered are cutting velocity, feed rate, depth of cut and step over. The second aim is to identify the effects of cutter path strategies when employing in pocket milling. The both aims will be addressed by means of using Taguchi parameter design. (c) 2007 Elsevier B.V. All rights reserved.