This work represents the results of research on thermal stability, oxidation resistance at temperatures of up to 800 degrees C and electrochemical behaviour of (Ti,Al)N-(similar to 3at.%)Cu and (Ti,Al)N-(similar to 8at.%)Ni nanocrystalline coatings in acidic and alkaline media. The coatings were deposited by the arc-PVD method with a thickness of approximately 4 pin and crystallite size of less than 20 nm. It has been demonstrated that the composition and properties of the coating structures do not change when the coatings are heated in 10(-4) Pa vacuum at temperatures of 600, 700 degrees C for 1.5 h. Heating up to 800 degrees C caused an increase of crystallite size and reduction microstrain in the crystal lattice of the ceramic phase. The process is accompanied by deterioration of the coating hardness from 48 to 52 to 33-36 GPa. The (Ti,Al)N-Cu and (Ti,Al)N-Ni metal-ceramic nanostructured coatings are characterized by heat resistance up to the temperatures of 700 and 800 degrees C respectively. The coatings under study have tendency for self-passivation and resistance to pitting corrosion. (C) 2016 Elsevier B.V. All rights reserved.