AA5083 (Al-4.4Mg-0.7Mn-0.15Cr) is a non-heat treatable aluminum alloy known for its excellent corrosion resistance. However, it can become susceptible to intergranular stress corrosion cracking (IGSCC) when exposed to temperatures ranging from 50 to 200degreesC for sufficient lengths of time. In this study, IGSCC response of sensitized 5083 was studied by constant extension rate testing (CERT) in aerated 3.5%NaCl solution under free corrosion conditions and under potentiostatic polarization. To aid in interpreting the CERT results, precipitation of beta (Al3Mg2) intermetallic particles on grain boundaries was characterized by transmission electron microscopy. Additionally, the dissolution characteristics of the beta phase were measured by potentiodynamic polarization of the compound synthesized in bulk form. CERT results showed that under open circuit conditions, measured ductility depended strongly on sensitization time, reaching a minimum at 189 hours. This trend correlated well with the fractional coverage of beta on grain boundaries. In polarization experiments, bulk synthesized beta was found to be spontaneously passive from its corrosion potential (-1.40V(sce)) up to about -0.92V(sce) where passivity was observed to breakdown. In CERT, sensitized samples polarized below the beta phase breakdown potential showed almost no evidence of IGSCC testing indicating that a high beta dissolution rate is a requirement for IGSCC.