Methyl-functionalized carbon nanocones of different geometries have been investigated using UFF, AM1, PM3, HF and DFT computational methods. It is shown that carbon atoms at the apices of the nanocones are more reactive the other carbon atoms in the cones. The results of this investigation suggest that it may be possible to selectively functionalize some nanocone carbon atoms by radicals, thus synthesizing novel systems with interesting properties. Additionally, vibrational spectra of methyl-functionalized nanocones have been calculated and analyzed. The results suggest the IR spectra of substituted nanocones should show at which position the substitution occurred. (C) 2007 Elsevier B.V. All rights reserved.