The stress corrosion cracking of several high chromium ferritic stainless steels in LiCl and MgCl2 solutions has been examined in terms of relevant electrochemical parameters. A low interstitial 26 Cr-1 Mo alloy (E-Brite) is immune to SCC at the open circuit corrosion potential; however, SCC is induced by anodic polarization revealing a critical cracking potential (Ecc) 15 mV noble to the corrosion potential. Plastic deformation and grain coarsening by high temperature annealing induce SCC by shifting Ecc in the active direction without affecting the corrosion potential. Nickel additions to high chromium ferritic stainless steels induce SCC by shifting the corrosion potential noble to Ecc. A close parallelism between the electrochemical response of austenitic and ferritic stainless steels is demonstrated suggesting that similar failure mechanisms occur in both types of steels. For the ferritic stainless steels, interrupted loading experiments reveal a hydrogen embrittled region in advance of stress corrosion cracks.