A novel, effective and sustainable strategy for the synthesis of aldehydes has been developed using inexpensive, readily available, oxygen-stable and recyclable CuFe₂O₄ nanoparticles as the catalyst. The corresponding substituted aldehydes were obtained in moderate to good yields by aerobic oxidation of aromatic alcohols in water under dioxygen atmosphere. Importantly, a ligand or a base was not necessary. The catalyst was completely recoverable with an external magnet and could be reused six times without significant loss of catalytic activity.