The influence of N₂⁺ and 11_B⁺ ion implantation on the near surface of 304 austenitic stainless steel having strained and strain-free surfaces has been studied. The samples were implanted in a Varian DF-3000 for 3 h at 2 × 10^-6 torr with N₂⁺ and 11_B⁺ ions accelerated to an energy of 130 keV at a dose of 2.5 × 10²¹ ions m^-2. The characteristics of the implanted layer and depth profile were investigated by Auger electron spectroscopy (AES) and electron spectroscopy for chemical analysis (ESCA). Scanning electron microscopy was also performed. Relative Knoop hardness numbers were measured at different test loads (19.6 to 490.3 mN). In the mechanically polished samples implanted with N₂⁺ and 11_B⁺ ions, a relative increase of 200 and 30%, respectively, is observed at the 19.6-mN test load. In the case of etched samples implanted with the same ions at the same load, a relative increase of 260 and 80% was observed. Iron nitride and boron nitride precipitates were inferred using ESCA. The increase in near-surface hardness is attributed to the formation of these precipitates and the process of dislocation pinning.