Macroscopic nanotube fibers, composed of aligned large diameter single-walled carbon nanotubes (SWNTs), were prepared by a simple CVD method. These fibers, which constitute the nanotube ropes of loose structure like hemp cords. can be divided into the nanotube threads (mesoscopically) and subdivided into nanotube bundles (microscopically). The samples show good alignment at different scales. The fibers, several micrometers in diameter, have a relatively stable structure and only dissociated partially under ultrasonic dispersion. The obtained SWNTs have good crystalline structure and good purity. The influence of the CVD conditions on the fiber morphology was also investigated. (C) 2003 Elsevier Science B.V. All rights reserved.