We have employed hot-wire chemical vapor deposition (HWCVD) for the growth of single- and multi-walled carbon nanotubes (SWCNTs and MWCNTs). The reactor consisted of a quartz tube and two tungsten filaments. Often additional molybdenum wires were incorporated into the system serving as additional heat sources and possibly providing via evaporation an additional gas-phase catalyst. Transmission electron microscopy indicated the presence of both types of CNTs with diameters ranging from similar to 1-30 nm. Thermal desorption experiments showed the presence of the both physisorbed and chemisorbed hydrogen. (c) 2005 Elsevier B.V. All rights reserved.