The creep-fatigue behavior of Cr-Mo steels has been examined from published data. The published data were compiled in an earlier effort and used in this paper to develop a multivariate best-fit equation to predict the low cycle fatigue life. The fatigue test temperatures were representative of temperatures experienced in nuclear power plants, which varied from room temperature to 600°C. Within this temperature range, depending upon the test parameters used, creep and fatigue processes interact and failure occurs in the lowcycle fatigue regime.