The stress corrosion crack growth rate response of alloy X750 was studied in high temperature water as a function of loading, corrosion potential, water purity, and heat treatment condition (AH and HTH). In addition to providing more quantitative data on the behavior of alloy X750, the response of this higher strength material is interesting to compare with similar materials whose yield strength is varied by cold work or irradiation. Key Words: alloy X750, stress corrosion cracking, high temperature water, crack growth rate, corrosion potential, water purity, stress intensity factor, nickel alloy, heat treatment, yield strength.