The preferential oxidation of carbon monoxide in the presence of hydrogen (PROX reaction) was studied on Cu catalysts promoted with Fe, Nb, Ce, and Ni supported on TiO₂ and on TiO₂ nanotubes. The surface area of the untreated TiO₂ anatase (150 m²/g) support was increase to 350 m²/g when transformed into TiO₂ nanotubes (NT). XRD and SEM results confirm the formation of nanotubular structures responsible of the increase in BET surface area. The activity results indicate that a 10% Cu/5% Nb/TiO₂-NT catalyst is highly active for this reaction compared to other transition metals and with a catalyst with the same composition supported on untreated TiO₂. We found close to 80% CO conversion and 40% selectivity to CO₂ formation at 170 °C. The higher activity is ascribed to a higher dispersion of Cu on the TiO₂ NT structures.