This study investigates the fatigue behavior of AlSi9Cu3 aluminum die-cast alloy after pre-exposure to accelerated environmental conditions (pre-corrosion). The research highlights the significant impact of corrosion, particularly localized corrosion within the microstructure, on the fatigue strength of this alloy. It introduces a numerically efficient fatigue assessment method for pre-corroded specimens, employing fracture mechanics principles. The investigations reveal the significance of considering short crack propagation in fatigue assessment especially for small corrosive defects. Polished specimens were exposed to an acidic aqueous salt solution to simulate accelerated real-world corrosive conditions. Experimental fatigue tests revealed a 34 % reduction in long-life fatigue strength for pre-corroded surface condition compared to polished condition. Numerical simulations, which treated corrosion as a crack-like surface imperfection, were used to estimate fatigue life and fatigue limit. These simulations provide conservative estimates for the examined initial flaws equal to the maximum corrosion depth. The variation in long-life fatigue strength for all examined flaw geometries ranged from 13.7 % above to 22.2 % below the experimentally determined fatigue strength of the pre-corroded surface. These findings highlight the necessity of incorporating short crack propagation in fatigue assessments, particularly for small corrosive defects, to ensure the reliability and safety of components in corrosive environments.