Purpose: The paper presents results on the mechanical and tribological properties examinations of the X40CRMoV5-1 hot work alloy tool steel alloyed with carbide powders using the high power diode laser (HPDL).Design/methodology/approach: Metallographic examinations of the material structures after laser alloying of their surface layer were made on light microscope. The tribological wear relationships using pin-on-disc test were specified for surface layers subject to laser treatment, determining the friction coefficient, and mass loss of the investigated surfaces. Hardness tests were made with Rockwell method in C scale on specimens subjected to the standard heat treatment and alloyed using the high power diode laser at various parameters. X-ray diffraction (XRD) technique was used to investigate crystalline structure and phases in the layers.Findings: Metallographic examinations carried out on the light microscope confirm that the structure of the material solidifying after laser remelting is diversified, which is dependant on the solidification rate of the investigated steels. The investigations carried out made it possible to state that due to the heat treatment and remelting of the X40CrMoV5-1tool steel with the WC, TaC or TiC powders it is possible to obtain the high quality surface layer with no cracks and defects and with hardness significantly higher than the substrate metal.Research limitations/implications: In order to evaluate with more detail the possibility of applying these surface layers in tools, further investigations should be concentrated on the determination of the thermal fatigue resistance of the layers.Practical implications: The alloyed layers which were formed on the surface of the hot work steel have shown significant improvement. Good properties of the laser treatment make these layers suitable for various technical and industrial applications.Originality/value: A modification of tool steels surface using a laser beam radiation, as well as coating them with special pastes containing carbides particles such as tungsten, tantalum and titanium allows the essential improvement of the surface layer properties – their quality and abrasion resistance, decreasing at the same time the surface quality.