Aluminium nitride films were deposited by reactive sputtering on steel substrates (H 11) with the aim of realising anti-corrosion coatings. The porosity of the films combined with their inadequate thickness cause the good initial corrosion resistance of the samples to decrease drastically during immersion time in a 0.5 M NaCl solution. In order to create a corrosion barrier between AlN and steel, three types of under-layers were investigated: nickel under-layers (with a thickness of about 10 mum) deposited by both electrochemical and electroless methods, and titanium under-layers (with a thickness of about 1 mum) obtained by sputtering. The structure and morphology of the samples were studied from X-ray diffraction (XRD), atomic force microscopy (AFM) and scanning electron microscopy (SEM) observations. Electrochemical impedance spectroscopy (EIS) tests versus immersion time were carried out in a 0.5 M NaCl solution in order to compare their corrosion resistance. It appears that AlN/electroless nickel shows the best corrosion resistance, whereas the AlN/electrochemical nickel and AlN/titanium samples are almost in the same range.