Optical absorption measurements have been made on BaTiO3thin films prepared by rf sputter deposition. An amorphous and a distinct microcrystalline phase have been studied in addition to the normal crystalline phase. A sharp absorption threshold is obtained at 3.6, 3.95 and 4.3 eV for the crystalline, microcrystalline, and amorphous phases, respectively. The increase in gap correlates with an increasing lattice parameter.