High-temperature low cycle fatigue (LCF) behavior of the super alloy Udimet 720 has been investigated in SO2-containing atmosphere under the influence of salt deposits and various stress levels. Test conditions were adjusted to control the  atmosphere and temperature during the cyclic loading. The damage initiation was monitored by means of the potential drop method. Fracture surfaces and microstructural features in their vicinity were analyzed to explore the interaction between mechanical and corrosion damage at high temperatures and different stress levels. In general, the applied salt deposit impairs the fatigue lifetime at all tested stress levels. The degradation in fatigue life, however, is more pronounced at the highest applied stress level and for test durations that are long enough to cause corrosion-induced damage at relatively low stresses. Interestingly a pre-oxidation treatment (under the same test temperature and atmosphere) for the specimens with salt-deposit prior to the LCF tests results in a clear reduction in the fatigue lifetime particularly at relatively low stresses. LCF tests with an applied dwell time at the maximum applied stress (on specimens with salt-deposit) showed the shortest fatigue lifetimes. Microstructural analysis of the fracture surfaces and the material underneath the corroded layers emphasize the importance of the pre-corrosion damage for the fatigue life particularly in the low stress range. It seems that the corrosive deposit reacting with Cr-oxide as well as Ni-oxide (at a later stage) tends to break during mechanical loading allowing the ingress of corrosive species that promote internal corrosion (basically sulfides) at the grain boundaries with depths of around 10 – 15 µm. This study suggests different damage mechanisms depending on both the stress range and the presence of pre-corrosion damage. At low stress levels, a corrosion-induced and corrosion-controlled damage mechanism prevails, whereas at high stress levels the damage initiation may be associated with the presence of the pre-corrosion damage.