The aim of this study is to investigate the influence of environmental factors, including pH, chloride ion, and pitting inhibitor, on the fatigue properties of AISI 347 stainless steel. Systematic fatigue tests, including both high-cycle fatigue (HCF, S-N curves) and fatigue crack growth (FCG, da/d N-DeltaK curves), have been conducted in air and several aqueous environments. Results showed the HCF strength was markedly reduced in an acid solution and in a chloride-containing solution, as compared to the air value. An addition of pitting inhibitor could restore the HCF strength in salt water back to the level in atmospheric air by preventing the formation of corrosion pits and decreasing the corrosion rate. However, the corresponding stage II FCG rates in all given environments were almost equivalent. These results indicated that the variation of chemistry in bulk environment exerted more influence on the fatigue crack nucleation than on the extension of long fatigue cracks. (C) 2004 Kluwer Academic Publishers.