Fatigue failure at room temperature in most structural metals and alloys occurs by the rapid initiation and subsequent controlled propagation of a surface crack. Propagation is transgranular and is controlled to a large extent by continuum plasticity effects ahead of the crack. With increasing temperature, other factors affect this simple fatigue process; namely, the weakening of grain boundaries leading to intergranular propagation, the initiation and growth of other cracks in the bulk of the material by creep processes, and the more rapid oxidation effects which can occur at elevated temperatures. This paper shows the extent to which continuum material properties still control fatigue failure in elevated temperature situations, by reference to recently developed theories and the observed fatigue behavior of a stainless steel and a magnesium alloy over a range of temperatures (up to 0.73 Tm) and strain rates. The influence of secondary creep fracture is examined in the light of results of holdtime tests.