Abstract Titanium nitride coatings are being used increasingly for various technological applications because of their outstanding mechanical and technical properties such as colour, chemical inertness and ultrahardness. A marked change in these properties was found when changing the nitrogen partial pressure during the growth process of the TiN coatings. Although 15N constitutes only 0.37% of natural nitrogen, the nitrogen content and distribution through the depths of various TiN layers were determined by using the nuclear reaction 15N(p, αγ 12C based on the resonance at 1.65 MeV. This allowed TiN coatings with thicknesses between 1 and 6.4 μm to be analyzed, attention being paid to the presence of the 1.21 and 1.98 MeV resonance peaks. Results showed that an increase in nitrogen partial pressure results in an increase in relative nitrogen content in the coatings.