Catalytic oxidation of dichloromethane (DCM, 1000 ppm) in wet air was investigated over PtHFAU catalysts differing by their Pt content (from 0 to 0.87 wt.%) the Si/Al ratio being constant and equal to 5. For a given temperature, the rate of DCM transformation is independent of the platinum particles size and of the platinum content. On the other hand, DCM oxidation into CO2 occurs through a bifunctional mechanism: DCM was firstly hydrolysed into HCl and formaldehyde on the Bronsted acid sites of the support. Afterwards, formaldehyde was oxidised into CO2 and H2O On the platinum sites. A reaction scheme was proposed to explain the complete oxidation of DCM over PtHFAU catalysts. (C) 2004 Elsevier B.V. All rights reserved.