The growth of diamond films on various polycrystalline metal and (001) Si substrates by biased hot‐filament chemical vapor deposition is discussed. The deposited films have been characterized by scanning electron microscopy, x‐ray diffraction, Auger electron spectroscopy, and Raman spectroscopy. Films grown on Si, Ni, and W exhibited the best quality according to Ramansp3/sp2peak intensity ratios and the full width at half maximum of the 1332 cm−1Raman peak. The relationship between this quality and substrate properties such as surface energy and lattice parameter is discussed. Also, the residual stress in the film as measured by the Raman peak shift is correlated with the thermal expansion coefficient of the substrate.