Hardmetals, commercially called Widia, are the most researched and developed representatives of powder metallurgy materials in the metal cutting industry. The development of these materials nowadays is based on the application of ultrafine and nano sized powders for sintering which significantly improve the properties of the product, allow application at higher cutting speeds, lower tolerances and longer tool life. The most important way to increase the tribological properties of tools is certainly to coat them with thin hard coatings. Coated hardmetals currently account for 80-90% of cutting tool production thanks to their unique combination of wear resistance and toughness as well as the ability to form complex shapes. By surface processes (modification and / or coating) it is possible to form a surface layer / base material system with properties that can meet modern expectations with acceptable production costs. However, commercially available cemented carbide tools have not yet stepped into the nano range and their grain size of the carbide phase after sintering is higher than 200 nm. The reason for this lies in the current cost of production of cemented carbide tools below the nano grain size, the complexity of the sintering process, and the high purity of the environment in which such tools are produced in laboratory conditions. Accordingly, the coating procedures used on such tools are relatively older because in practice they have proven to be sufficient to create a compact layer of base material - coating. As nano materials are highly reactive, both in the sintering and coating phase, when using chemical vapour deposition process (CVD) at around 1000 °C on the surface of the tool, microstructural defects are formed that disrupt one of their most important properties, which is toughness. The reduction of the coating temperature is enabled by applying of one of the most modern surface engineering technologies, ie. plasmaassisted chemical vapour deposition (PACVD) process. The PACVD process, which is nowadays still insufficiently studied on hardmetals, uses plasma to lower the coating temperature to about 500 °C. In the framework of this doctoral thesis, a cemented carbide tool with 5 wt. % Co, 10 wt. % Co and 15 wt. % Co was successfully sintered, and by the use of plasma-assisted chemical vapour deposition, with the aim of improving properties of these tools, new and innovative systems base material/coating were produced, which were until now unknown and unexplored in practice. The theoretical part of the paper describes in detail the process of obtaining a sintered cemented carbide product, describes the technical requirements that are placed on cutting tools in terms of their properties and explains the mechanisms of wear of cemented carbide tools. The PACVD process is described in detail from the perspective of coating hard metals and the mechanisms of forming layers have been explained. The experimental part is divided into two parts, the first of which refers to the implementation and validation of the success of sintering of nano-sized hardmetal, and the second involves the application of coatings on the produced material. In the first section of the experimental part, the characteristics of the initial powder mixtures are described in detail, as well as the procedures that preceded the sintering by the Sinter HIP process. Nano-sized grain formation, without the presence of unwanted microstructural defects, was confirmed by XRD testing, microstructural analysis and carbid grain size determination on a scanning electron microscope with field emission (FESEM), but also by indirect non-destructive characterization methods such as measuring magnetic properties. Of the mechanical properties, the most important properties of hard metals were examined, namely hardness and fracture toughness, and the obtained results were compared with the literature values for hardmetal materials of identical grain size of the carbide phase. The second part includes the PACVD coating process with an emphasis on the development of new innovative coating systems, coating/base material. By determining the crystal structure by the XRD method, it was confirmed that the PACVD process does not cause the formation of microstructural defects on the surface of the base material. Characterization of the obtained surface layers was performed by microstructural analysis using light and electron microscopy, surface roughness determination, coating adhesion testing by scratch test method and Rockwell C indentation method, coating thickness measurement by calotest method and microhardness test of coatings. In order to quantify the impact of newly developed surface layers on the properties and durability of cemented carbide tools, erosion wear testing (particle erosion), determination of friction and sliding wear factors (pin on disc), but also testing of tool durability by single point turning test was performed. Based on a comprehensive analysis of the obtained results, it was concluded that PACVD coating process can achieve significant improvements in the tribological and mechanical properties of cemented carbide cutting tools.