Laser surface melting of Ti-6Al-4V alloy under a pure nitrogen environment was carried out with Nd:YAG pulsed laser. The microstructure, hardness, wear and corrosion behaviour of the nitrided samples were examined, using scanning electron microscopy, XRD, XPS, microhardness measurements, fretting test and anodic polarization tests i HCl and HNO 3 solution. For comparison, untreated samples were tested under the same conditions. The microstructures consisted mainly of a thin continuous layer of TiN followed by nearly perpendicular dendrites, and below this, a mixture of small dendrites and large needles, which had a random orientation. The dendritic structure was the TiN phase, the needle phase was TiN 0.3 and the matrix was nitrogen-enriched . An improvement in corrosion behaviour, associated with the presence of a good TiN coating, was observed. However, if the polarization potential is higher than threshold, or the period of immersion is sufficiently long, then the laser treated specimens will be attacked with a corrosion rate higher than untreated Ti-6Al-4V alloy. The density of TiN dendrites decreased gradually towards the interface between the nitrided layer and the substrate. The melted zone showed a range of hardness of between 400-1300 HV, this could be due to the enhanced fretting wear behavior of laser nitrided samples