Nanospray has been shown to be a viable ionization method for analysis of fullerenes and fullerene derivatives by mass spectrometry. The sample quantities required have been comparable to those used for matrix-assisted laser desorption/ionization, which is currently considered to be amongst the most sensitive techniques. No modification of the fullerene sample solution was required. Neither protonation nor deprotonation were ever observed during nanospray of fullerenes, leading to the conclusion that an alternative to the traditionally accepted ionization mechanism is required. The spectra were free of fragmentation, allowing the molecular ion to be identified beyond doubt.