Communication: Carbon nanotubes containing HfC crystals (see Figure) have been synthesized during the de are discharge of a Hf-composite graphite electrode. Clear evidence is presented of the Hf-catalyzed growth of the nanotubes based on transmission electron microscope images- and the growth mechanism, which is thought to be completely different to that active in the production of vapor-grown carbon fibers or metal catalyzed nanotubes, is discussed.