Multiwall carbon nanotubes were grown on Fe:Co:CaCO3 catalysts by catalytic chemical vapor deposition (CCVD) method using two heating methods, external oven and RF inductive heating. Comparative analysis of the nanotubes obtained by the two methods showed that inductive heating generates nanotubes with smaller external diameters, smaller number of walls, an aspect ratio in the range of hundreds, and with a ratio of the outside to the inside diameter ranging between 2 and 2.5. RF heating CCVD is an attractive method for growing carbon nanotubes because of the advantages it presents relative to the enhanced control ability of the growth process. (c) 2006 Elsevier B.V. All rights reserved.