In this study, the microstructure and corrosion resistance of the stir zone (SZ) of the AA2198-T8 Al-Cu-Li alloy welded by friction stir welding (FSW) were investigated by microscopy, immersion tests and electrochemical techniques such as measurements of open circuit potential variation with time, and scanning vibrating electrode technique (SVET) measurements. A low chloride-containing solution (0.005 mol L−1 NaCl) was employed in the corrosion studies and severe localized corrosion (SLC) was observed in the SZ related to intergranular attack. The results were compared to those of the non-affected areas by FSW, also known as base metal (BM). In the BM, SLC was found and the type of attack related to it was intragranular. In both zones, BM and SZ, SLC was due to precipitates of high electrochemical activity, specifically T1 (Al2CuLi) phase in the BM, whereas TB (Al7Cu4Li) / T2 (Al6CuLi3) in the SZ. Scanning vibrating electrode technique (SVET) analysis was very useful in the study of SLC in the AA2198-T8 alloy showing the development of high anodic current densities at the mouth of the SLC sites. •The BM and the SZ of the AA2198-T8 FSWed presented SLC when tested isolated.•Corrosion attack was intragranular in the BM and related to T1 phase.•Corrosion attack was intergranular in the SZ and related to T2/TB phase.•Current densities for SLC are lower in the SZ comparatively to the SLC at the BM.