Strength of metal foams is enhanced by anodizing. The strength increase may not be immediately apparent, but may require aging. Anodization is preferably carried out by applying voltage across a cathode (in contact with the electrolytic bath) and the foam anode and then immersing the anode in the bath. Improved results are also obtained if surfaces not to be anodized are not contacted with the electrolytic bath. The electrolyte can optionally contain a fluorine acid such as HF and HBF4. These tend to make the foam less porous. Preferred foams are made of aluminum base metals.