Carbon nanotubes were grown on thermally oxidized porous silicon by catalytic chemical vapor deposition from the mixture of ferrocene and xylene precursor. The growth rate of carbon nanotubes showed dependence on the oxidation extent of porous silicon. On pristine porous silicon surfaces, only poor nanotube growth was observed, whilst samples oxidized in air at 200, 400, 600 and 800 degrees C prior to the deposition process proved to be suitable substrates for carbon nanotube synthesis. Networks of carbon tubes with diameter of similar to 40 and similar to 10 nm observed on the surfaces of samples were investigated by electron microscopy and by energy dispersive X-ray analysis. (c) 2005 Elsevier B.V. All rights reserved.