Résumé : The EN 3665 test is used to compare the filiform corrosion of aluminium substrates pretreated with Cr6+ and coated with different powder paints. The influence of the mechanical properties (tensile test and adhesion test), the chemistry (DSC and FTIR analysis) and the physical properties (oxygen and water permeations) of the paints on filiform corrosion is measured. The corrosion promoted filaments are studied morphologically and electrochemically. Their growth seems to be due to a combination between specific mechanical properties of the paints and their adherence on the pre-treated substrates. The influence of the paint thickness is also illustrated. © 2001 Elsevier Science B.V. All rights reserved.