A series of stress corrosion cracking(SCC) tests were carried out on the peakaged Al-Li-Cu 2090 alloy plates to examine the effect of zinc addition on static- and dynamic-SCC properties. The alloy with 0.7% zinc addition showed an improved static-SCC resistance in the S-L direction. The reference 2090 alloy exposed to aqueous sodium chloride solution exhibited an accelerated dynamic-SCC growth in the T-L direction, relative to exposure to laboratory air, while the alloy with zinc addition revealed a reduced environment-sensitive crack growth. The dynamic-SCC was transgranular, showing a repetitive saw-tooth crack path, which is assumed resulting from localized planar slip associated with{110}<211>texture and inhomogeneous distribution of T₁-precipitates. It was found that Zn addition is effective in reducing the slip planarity and preferential dissolution along slip bands.