The recently developed, novel superhard nanocrystalline compositesnc-TiN/a-Si3N4have been investigated by means of high resolution transmission electron microscopy. The microstructure consisting of nanocrystalline TiN imbedded withina⩽1 nmthin amorphousSi3N4,the relative amount of both phases, and the TiN-crystallite size which were previously determined by means of x-ray diffraction and energy dispersive analysis of x rays have been directly confirmed.