Ferroelectric PbTiO3 thin films were grown on Si(100) substrates by metalorganic chemical vapor deposition via thermal pyrolysis at relatively low temperature (approximately 500-degrees-C) using Pb(tmhd)2, Ti(OC3H7)4, and N2O. Transmission electron microscopy results suggested that the grown PbTiO3 films were polycrystalline layers. Auger depth profiles indicated that the compositions of the as-grown films consisted of lead, titanium, and oxygen uniformly distributed throughout the films and that the films exhibited smooth interfaces. These results indicate that the growth of polycrystalline PbTiO3 layers instead of epitaxial films originated from the formation of an interfacial amorphous layer prior to the creation of the films. Further, a mechanism for the formation of an interfacial layer between the PbTiO3 thin films and the p-Si substrates is presented.