Constant extension rate tests (CERT) were used to evaluate the susceptibility of two cold rolled nickel strip materials to environmentally assisted cracking (EAC) in 1.5M LiAlCl4/SOCl2 One strip,material was made by a powder metallurgy (PM) process that started with carbonyl nickel. The other was cast and wrought (C&W). Both were 0.05 mm thick and cold-rolled to the three-quarter hard condition. The bulk impurity concentrations, grain structures, and mechanical properties of these two materials were similar. However, the C&W alloy was distinguished by a substantially higher bulk manganese content and oxygen-rich inclusions, a large fraction of which also contained sulfur. EAC of the PM ahoy manifested principally as intergranular fracture, occurred in samples that were polarized to -50, 0, and +200 mV (Li/LiCl), but not in ones that were freely corroding at +3.65 V (Li/LiCl). These results are consistent with EAC being caused by a mechanism involving zero-valent lithium, proposed by Scully et al.(1) In marked contrast to the PM alloy, the C&W alloy exhibited no susceptibility to Li-assisted cracking. In ancillary experiments, performed with samples that were cathodically charged with hydrogen, only the PM alloy exhibited a high susceptibility to intergranular cracking. The present results indicate that subtle microstructural differences may affect the reliability of Li/SOCl2 cells. Although the existing evidence is circumstantial, the results also suggest that lithium-assisted and hydrogen-assisted intergranular cracking have analogous sensitivities to grain boundary segregation of sulfur.