Friction stir welding has been considered as an alternative to fusion welding processes ofstainless steels. A lean duplex stainless steel, grade UNS S82441, has been recently developedand is prone to localized corrosion, such as pitting when exposed to harsh conditions duringuse. However, pitting resistance of UNS S82441 has not been previously investigated. In thisstudy, UNS S82441 lean duplex stainless steel was friction stir welded, and its microstructureand localized corrosion resistance were investigated by phase volumetric fraction, scanningelectron microscopy, transmission electron microscopy and electrochemical tests. The pit-ting resistance of each zone was investigated by polarization tests and by determining thecritical pitting temperature. The results indicated that microstructural changes promotedby friction stir welding affected the pitting resistance of the lean duplex stainless steel.