The corrosion behaviour of sputter-deposited, Al–W coatings with three different concentrations of tungsten (0.6, 3.5 and 11at.% W) on AA7075 aluminium alloy substrates was investigated in chloride media using EIS, salt-fog tests and surface analyses. The surface analyses were performed with XPS/AES, SEM/EDS and TEM microscopy. The presence of W reduces the thickness of the oxide layer formed after the EIS test, as proved by the compositional depth profile. From the EIS data of the investigated Al–Wx coatings, the polarisation resistance (Rp) and the capacitive behaviour as a function of the immersion time were obtained. A small increase in Rp suggested improved corrosion properties over time. However, the extent of the improvement depends on the content of W and the coating-surface morphology (the presence of growth defects on the coating surface). The capacitive behaviour observed at high frequencies was related to the dielectric properties and the thickness of the barrier oxide film formed. The salt-fog tests to some extent supported the results from the EIS measurements. However, there was a difference between the corrosion EIS and salt-fog test results in the case of the Al89W11 coatings. The thickest oxide layer and the “layering” into the three regions (porous, semi-porous and intact) were observed when the salt-fog corrosion test was performed on the Al89W11 coating. Galvanic corrosion, probably due to the local compositional and structural inhomogeneities, takes place. However, this was not unambiguously observed during the EIS corrosion test.