Double-walled carbon nanotubes with a narrow distribution of diameters have been synthesized by catalytic CVD of methane over Fe-Co/MgO catalyst. The as-synthesized double-walled carbon nanotubes were characterized by scanning electron microscopy, high-resolution transmission electron microscopy and Raman spectroscopy. The obtained double-walled carbon nanotubes have an inner and an outer diameter of 0.6-1.2 and 1.3-2 nm, respectively. Raman analysis and high-resolution transmission electron microscopy observation indicated that the prepared double-walled carbon nanotubes were of high quality. © 2005 Elsevier B.V. All rights reserved.