PurposeThis paper seeks to report a preliminary study that was conducted in order to investigate the corrosion behavior of aluminum surfaces in aqueous solution in the presence of microorganisms. For this purpose, the fungus Aspergillus niger was tested in chloride‐containing aqueous media.Design/methodology/approachWeight loss and pH measurements were performed to verify the activity of the fungus on the aluminum surface and the atomic force microscopy technique was used to examine the surface after removing the biological film.FindingsThe pH of the media depended on the immersion time. Pitting attack was observed on the surface. The findings confirmed that the corrosion reaction of the aluminum was catalyzed by the presence of fungus and, simultaneously, the mean roughness of the aluminum surface was altered. After removing the biofilm, fungal hyphae hallmark was evident.Originality/valueUp until low, relatively few studies have addressed biofilm attack on materials, and especially attack on metallic surfaces in media contaminated by fungi. Hence, this paper is important for its contribution to the body of knowledge about biofilm action on metallic surfaces.