Carbon nanotubes (CNT) are unique nanostructures with remarkable electronic and mechanical properties and could be used, for example, in nanometre-sized electronics or to strengthen polymer materials. Today, both SWNT and MWNT are being used as key components in the production of high-strength composites, and advanced sensors, electronic and optical devices, catalysts, batteries and fuel cells. Patenting activity in this sub-field of nanotechnology registered a spurt during the last 12 years-implying a breakthrough bringing about a technological paradigm shift in the field of fullerene since carbon nanotubes are fullerene-related structures. CNT is, thus, one of the key technologies likely to revolutionize information technology, materials and medicine and the present study aim to examine technological developments in this field based on international patenting activity during the period of 1991-2003. (C) 2004 Elsevier B.V. All rights reserved.