An endohedral methane complex of a fullerene, derivative is first synthesized by insertion of a methane molecule through the opening of an open-cage C-60 derivative. The trapped methane is confirmed by NMR spectroscopy and mass spectrometry. Both methane carbon and protons show remarkable upfield shifts in NMR, characteristic of a chemical species in a fullerene cage. CH4 protons appear as one equivalent signal in the H-1 NMR spectrum, suggesting that even methane can rotate in a C-60 cage.