Pt-doped TiO2/MWCNT composites have been prepared by the sol-gel route and tested in resistive devices for the low temperature monitoring of hydrogen. A morphological and microstructural investigation by SEM, TEM, XRD and micro-Raman spectroscopy of the composites was carried out. Results indicated that, regardless the nominal C/Ti molar ratio, only the anatase phase of titania is formed. Thin films of the Pt-doped composites, deposited on interdigitated ceramic substrates, showed promising hydrogen sensing at low temperatures. On the basis of the results obtained, some hypotheses on the sensing mechanisms operating on these nanostructured hybrid materials have been formulated.