The aim of this thesis was to investigate and develop polyaspartic coatings with nanosilica fillers modified with amino groups (NH2-) in order to enhance adhesion of coating on metallic surfaces and increase the productivity of the protective coating. The idea was to develop polyaspartic coating formulations for applying directly to metal surfaces (DTM). For this purpose, seven samples of polyaspartic coatings with different amounts of nanosilica filler of 20–30 nm in size were prepared. The coatings were applied on 2 mm thick low carbon steel panels prepared according to surface preparation standard Sa 2.5. The samples were characterized by mechanical testing with respect to hardness, adhesion, bending and impact resistance. The results showed that only 2% of the nanosilica per total mass of formulation improved adhesion of the coating to the surface of the substrate and that it was possible to apply the coating directly to the metal surface. Also, nanosilica filler changed the functionality of other particles or fillers, increased hydrophobic and oleophobic coating characteristics, altered rheology and thixotropy properties of coatings. After finalizing the formulation, degradation of coatings was analyzed by the electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) methods as well as by exposure of applied coatings to salty atmosphere in a salt spray chamber. No agglomeration and excellent compatibility of nanoparticles with other components in the formulation was observed. The main advantages of the modified polyaspartic coating were fast curing, fast drying time, excellent mechanical and chemical resistance and high film build which made it possible to reduce the number of coats in a coating system. The polyaspartic coating system with improved coating adhesion increased the durability of coating system and reduced volatile organic compounds (VOC) emissions and overall cost of the coating application process.