High-speed machining is a highly effective production method to achieve the following goals: increased machining productivity, enhanced quality of the machined surface, improved machining economy, improved ecological impact of machining. The objective of this research was to study the technological factors which influence the 3D surface roughness parameters in high-speed milling of two different types of die steel. The factors analysed were the feed rate, overlap and strategy. The depth of cut and cutting speed were kept constant. This article is based on the technological experiment performed in the Department of Mechanical and Materials Engineering of the Polytechnic University of Valencia and measurements of the 3D surface topography in the Mechanical Engineering Institute of Riga Technical University.