Corrosion attack is implemented on the aluminum alloy AISI 6063-T5 for six different non corroded and pre-corroded specimens. Concerning pre-corroded specimens, they are divided in two groups; the first one is immersed for 1 and 2 minutes in hydrochloric acid with 20% concentration, and the second group for 2, 4, 6 minutes of immersion but in HCl with 38% of concentration. Rotating bending fatigue tests are carried out on corroded and non-corroded specimens at the frequency of 50 Hz, at room temperature and without control of environmental humidity. Loading conditions are fixed by Finite Element numerical simulation; the loading ranges are 90%, 80%, 70% and 60% of the yield stress of this aluminum alloy. A numerical simulation study is carried out by means of the Ansys software to investigate the stress concentration factor variation induced by the proximity of two close pitting holes: in longitudinal and transversal direction regarding the principal applying loading. Finally, optical microscopy is used to analyze the fracture surfaces in longitudinal and transversal directions, in order to establish possible causes of fatigue fracture.