A series of polybenzoxazine-silica hybrids was papered by blending benzoxazine monomer with various ratios of tetraethoxysilane (TEOS) as a precursor for silica. The blends after hydrolysis and condensation of TEOS were thermally treated gradually up to 240degreesC to afford the hybrids. The IR spectra and DSC showed the completion of the ring opening of benzoxazine monomer and formation of silica by the end of the 240degreesC cure. The inclusion of silica into polybenzoxazine matrix has a noticeable effect on the thermal and mechanical properties.