High current, short length ion beam pulses appear to be a new alternative for surface property modification of solids, due to the combined effect of ion implantation with induced fast heating-cooling which this process presents. The repetitive pulsed nitrogen implantation (with a low energy plasma focus) of pure titanium with different pulse lengths (300 and 400 ns), and fluences per pulse ranging between 1.4 x 10(14) and 1 x 10(15) cm(-2), with total accumulated fluences between 7 x 10(14) and 1.6 x 10(16) showed a surface heating effect with important compositional and physical changes in the layers close to the surface. XPS analysis showed TiN0.8, formation independent of the total range of fluences used, with an increase in the superficial microhardness, when short pulse lengths were used. A correlation between the N/Ti concentration ratio, the binding energy difference (Ti2p(3/2)-N1s) and the x value in the stoichiometry of the TiNx compound formed was observed for the long pulse length case.