[en] The authors have nitrided Ti-6Al-4V alloys using excimer laser pulses at 1.2 J-cm^-2 in high purity N₂ at approximately one atmosphere. Substantial nitrogen and some oxygen incorporation resulted from multiple pulse processing. Formation of a TiN surface film was not observed. They have examined the tribological and mechanical properties of these surfaces using pin-on-disk and nanoindenter techniques respectively. Nitrogen alloying results in reduced friction and torque noise in the pin-on-disk measurements. At higher N concentrations, very little wear is observed, even after the friction behavior suggests surface deterioration. This is consistent with the formation of a transfer film at the sliding interface. Nanoindenter measurements of the surfaces show increasing hardness proportional to nitrogen incorporation. The tribological improvements can therefore be ascribed to a combination of increased surface hardness and tribochemical effects