This paper deals with the direct nitriding of titanium by laser in a nitrogen atmosphere. A nitrogen plasma is created at the sample during irradiation. A study of the plasma is presented, followed by chemical analysis of the irradiated zones for different experimental conditions with varying gas pressure, laser power density and irradiation duration. Helium was added to N2 to limit the development of a detonation wave in the plasma and which damages the surface. However, nitrogen dominates helium in the plasma and the effect is negligible. Working with pure N2 gas at pressures below 450 Torr is not favourable to the synthesis of TiN. The best results are obtained with a moderate laser power density and a limited number of laser shots, in pure nitrogen (760 Torr). Analysis shows that the synthesized layer is composed of titanium nitride and oxynitride with a thickness of 3 mum.