Functionalisation of carbon nanotubes is expected to improve their utility in a range of applications. This paper describes a method of silylating multi-walled nanotubes that have first been acid treated in order to introduce polar surface groups. A range of reagents were tested and N-(tert-butyldimethylsilyl)-N-methyltrifluoroacetamide (MTBSTFA) or 1-(tert-butyldimethylsilyl)imidazole (TBDMSIM) were found to be most effective. Products were characterised using EDX, FTIR, and UV spectrometry. (C) 2002 Elsevier Science B.V. All rights reserved.