Si–Cr–N coatings are promising candidates for protective coatings for materials with a poor resistance to oxidation at elevated temperatures. In this article, we examine and present the thermal stability and high temperature oxidation behavior of reactively magnetron sputtered Si x Cr y N z coatings with high content of silicon (>30at.%) and N/metal ratios of 0.48 and 1.1. These coatings are investigated under isothermal and dynamic conditions using differential scanning calorimetry and thermal gravimetric analysis for temperatures of up to 1400°C. The structure and morphology of the oxidized coatings are studied by X-ray diffraction, and electron microscopy. As-deposited Si x Cr y N z coatings represent a composite system consisting of two chemically separated amorphous phases: a-SiN x phase and a-SiCrN phase. The decomposition process connected with N 2 release occurs in Si x Cr y N z coatings at an annealing temperature T a ≥1000°C in an Ar atmosphere and involves a formation of nanocrystalline hcp-Cr 2 N, Cr 5 Si 3 , hcp-Si 3 N 4 and hcp-CrSi 2 phases. These structural changes are reflected in an increase in hardness from 13.2GPa and 19.3GPa to 34GPa and 25.6GPa for Si 0.66 Cr 0.34 N 0.48 and Si 0.66 Cr 0.34 N 1.1 coatings, respectively. Si x Cr y N z coatings exhibit considerable oxidation resistance due to the formation of stable and dense Cr 2 O 3 scales. The rapid oxidation of Si x Cr y N z coatings starts as temperature T a reaches ~1090°C. The dense oxide scale of ~0.4μm is formed during isothermal oxidation of Si 0.66 Cr 0.34 N 1.1 coatings at the temperature of 1100°C for 48h.