A detailed N/O kinetic mechanism has been developed and tested in comparison with experimental data for N2O ignition, NO and NO2 decomposition at high temperatures. It consists of 27 reactions among 11 species. A sensitivity analysis reveals which reactions are critical for the quality of the modeling in particular experimental conditions. The choice of the rate constants for these reactions is discussed. Good agreement has been obtained for the ignition delays in the pure N2O and its mixtures with Ar, decomposition rates of the NO and NO2 in static reactors and behind shock waves. The modeling using recently suggested controversial rate constants for the key reactions N2O + O = N-2 + O-2 (8) N2O + O = NO + NO (9) has been performed as well. It is demonstrated that the use of too-low or too-high values of the reactions (8,9) rate constants is incompatible with available experimental data.