A batch method for the gas phase production of carbon nanotubes by the catalytic decomposition of acetylene has been developed. Metal clusters are formed by laser vaporization of solid nickel in situ in the hot reaction tube containing a mixture of acetylene and argon. The laser generated clusters act as catalysts for the growth of nanotubes. With this method multi-walled tubes were obtained with inner diameters of 3–10 nm and outer diameters of 10–100 nm, respectively. TEM analysis shows that the tubes are well graphitized. ©1998 American Institute of Physics.