In this Letter. we report a new method for the fabrication of carbon nanotubes (CNT) and nanowires where amorphous hydrogenated carbon nano-particles were used as precursor. without metal catalyst addition. In particular, depending on the process parameters. we obtained single walled nanotubes (SWNTs) with mean diameter 1.2 nm and carbon nanowires with mean diameter 250 nm. A discussion on the possible growth mechanism is also reported. (C) 2002 Elsevier Science B.V. All rights reserved.