Amphiphilic methanofullerene derivative 1 is water soluble and micellar aggregation has been evidenced by small-angle X-ray scattering measurements and UV/Vis spectroscopy. Thanks to the high solubility of 1 in polar solvents widely used in sol–gel processing, successful inclusion of 1 in the sol–gel could be easily achieved. The optical limiting properties of the doped sol–gel samples have been evaluated and a fast S1–S0 relaxation has been observed for these samples. This observation appears to be consistent with the presence of micellar aggregates of 1 in the sol–gel. Indeed, the interactions between the fullerene spheres of neighbouring molecules in the clusters may be at the origin of this fast S1–S0 relaxation as already shown in solid C60-films.