A microelectrochemical technique was applied to make clear the effect of Cr on the pit initiation behavior at MnS inclusions in Fe- Cr steels. MnS inclusions in Fe-5Cr, 12Cr, and 18Cr steels dissolved around 0 V (vs. Ag/AgCl, 3.33 M KCl), and their dissolution potential regions were independent of Cr contents in the steels. A stable pit was initiated at the inclusions around 0 V on Fe-5Cr and 12Cr in 0.1 M NaCl. In the case of Fe-5Cr, after the stable pit initiation, the surface dissolution was started from the pit. In contrast, no surface dissolution was observed on Fe-12Cr, even though the stable pit was generated. In micro-scale polarization, no stable pit was initiated at MnS inclusions on Fe-18Cr. Only metastable pitting was observed around 0 V. The repassivation ability of Fe-Cr alloys has an important role in the pitting events at MnS inclusions.