The fatigue behaviour of advanced, lightweight components made of aluminium alloys is influenced not only by mechanical loads, but also to a large degree by environmental conditions. These environmental conditions can be, for instance, higher temperature, or corrosive media such as de-icing salt in the area of mobility. Defects due to corrosion affect the fatigue strength of components significantly and therefore are of particular interest for various economic branches, such as automotive and aerospace. Approaches from linear elastic fracture mechanics have been widely applied for a fatigue assessment of internal and external material defects such as gas pores, shrinkage cavities or intermetallic phases. Localized corrosion attack, such as intergranular corrosion, can appear in almost crack-like forms. For this reason, a fatigue life assessment based on fracture mechanics, with consideration of short crack propagation, was realised in this thesis for pre-corroded specimens made of a dendritic AlSi9Cu3 die casting alloy. This aluminium alloy has a mean secondary dendrite arm spacing (SDAS) of 22 µm and a hardness of 121 HBW1/10. For the assessment concept, fracture mechanics parameters were determined using SENB and proportionally reduced miniature SENB specimens using the load increasing method. In order to verify the fatigue life assessment method, two S/N-curves were determined experimentally using specimens with polished and pre-corroded surfaces. The pre-corroded specimens were corroded in the laboratory at room temperature for 20 h in an acidic aqueous salt solution. Corrosion on the pre-corroded specimens occurred, similar to intergranular corrosion, localized in the eutectic regions with a maximum corrosion penetration of 295 µm. The results of the fatigue tests for pre-corroded specimens show a 34 % decrease of the fatigue strength at 10^7 load cycles compared to the polished specimens. The numerical crack growth simulations assume, that the corrosion was a crack-like surface imperfection with a depth equal to the maximum corrosion depth 295 µm. Elliptical cracks with different semi-axis ratios were assigned as flaw geometry. Taking into account the short-crack behaviour, the fatigue life estimation provides conservative results with a difference in long-life fatigue strength of 4.5 % - 31.8 % compared to the experimentally determined fatigue strength of the pre-corroded specimens.