The mechanical properties and surface topography of TiN/TiO2 coatings deposited by reactive magnetron sputtering on electron beam surface treated Ti5Al4V substrates were studied. The phase composition and crystallographic orientation were studied by X-ray diffraction. The hardness was investigated by nanoindentation test. The surface topography was evaluated using atomic force microscopy. The results show that polycrystalline TiN and anatase - TiO2 phases are present in all cases. The electron beam treatment (EBT) leads to a more symmetrical distribution of the heights in comparison with the untreated substrates, as well as to increase in the surface roughness. The hardness of the Ti5Al4V substrates before and after the electron beam treatment process increases which is due to the transformation α+β to α′ martensitic microstructure occurring due to the fast cooling rate after the melting process. EBT leads to increase the surface roughness from 8 nm to 25 nm for the deposition of TiN/TiO2 coatings on Ti5Al4V. The treatment of Ti5Al4V substrates leads to decrease in the hardness of the coatings - from 7 GPa to 6 GPa. The scratch tests of the coated samples confirm the decrease of the friction coefficient as compared with the uncoated substrates. •The mechanical properties and the topography of TiN/TiO2 coatings on Ti5Al4V substrates, deposited by reactive magnetron sputtering has been studied.•Polycrystalline TiN and anatase - TiO2 phases are present in all cases.•The electron beam treatment leads to an increase in the surface roughness.•The hardness of the Ti5Al4V substrates before and after the electron beam treatment process increase.•EBT of Ti5Al4V substrates leads to decrease in the hardness of the coatings - from 7 GPa to 6 GPa.