Diamond nucleation on silicon substrates is a very slow process unless the substrates are bias treated or scratched with diamond powder prior to diamond growth under chemical vapor deposition (CVD) conditions. In this report, we present our results concerning the effect of various organic coatings on CVD diamond nucleation on Si substrates. Results show that diamond can nucleate readily on Si coated with an organic layer even without scratching and biasing. The different organics used on Si became glassy carbon in the early stages of CVD diamond deposition. The glassy carbon coatings obtained from different organics as well as the diamond films grown on the glassy carbon/Si substrates were characterized by X-ray photoelectron spectroscopy (XPS), X-ray induced Auger electron spectroscopy (XAES), scanning electron microscopy (SEM), and Raman spectroscopy. The results are discussed in terms of the formation of glassy carbon which, in turn, enhances diamond nucleation.