Titanium nitride layers on titanium metal have been produced by glow discharge plasma nitriding in nitrogen gas and the structure and composition of the layers has been investigated as a function of gas pressure and substrate temperature. Plasma nitriding is used as a surface treatment to improve the wear resistance of titanium alloys. The development of precise analytical techniques plays an important role in gaining a clearer understanding of the mechanism and kinetics of the coating formation. Light element analysis has been carried out using RBS and NRA and nitrogen concentration depth profiles obtained to a depth of 4-5 μm. The extent of oxygen contamination was measured using NRA and electronprobe microanalysis (EPMA). X-ray diffraction (XRD) was used to investigate the degree of preferred orientation in the coatings and also provide information on the amount of various nitride phase (TiN, Ti 2N) present in the coating.