Aluminium nitride coatings were formed on stainless steel substrate by DC-reactive balanced magnetron sputtering at various nitrogen concentrations in the sputtering gas mixture, and different substrate temperatures. The electrochemical corrosion behaviour of the coatings obtained was studied in 0.5 M H2SO4. Continuous improvement in corrosion resistance of the coatings was observed with increasing coating deposition temperature up to 500 °C. The corrosion potential shifted from −0.66 VSCE at 100 °C to −0.33 VSCE at 500 °C. Accordingly, the corrosion current density decreased significantly with increase in the deposition temperature. However, no major difference in corrosion behaviour could be noticed for the coatings formed at various nitrogen concentrations.