Abstract The microstructure of thin films grown by microwave plasma-enhanced chemical vapor deposition (MPCVD) from fullerene C 60 precursors has been characterized by scanning electron microscopy (SEM), selected-area electron diffraction (SAED), bright-field electron microscopy, high-resolution electron microscopy (HREM), and parallel electron energyloss spectroscopy (PEELS). The films are composed of nanosize crystallites of diamond, and no graphitic or amorphous phases were observed. The diamond crystallite size measured from lattice images shows that most grains range between 3–5 nm, reflecting a gamma distribution. SAED gave no evidence of either sp 2-bonded glassy carbon or sp 3-bonded diamondlike amorphous carbon. The sp 2-bonded configuration found in PEELS was attributed to grain boundary carbon atoms, which constitute 5–10% of the total. Occasionally observed larger diamond grains tend to be highly faulted.