Crystalline LaAlO 3 was grown by oxide molecular beam epitaxy (MBE) on Si (0 0 1) surfaces utilizing a 2 ML SrTiO 3 buffer layer. This SrTiO 3 buffer layer, also grown by oxide MBE, formed an abrupt interface with the silicon. No SiO 2 layer was detectable at the oxide–silicon interface when studied by cross-sectional transmission electron microscopy. The crystalline quality of the LaAlO 3 was assessed during and after growth by reflection high energy electron diffraction, indicating epitaxial growth with the LaAlO 3 unit cell rotated 45° relative to the silicon unit cell. X-ray diffraction indicates a (0 0 1) oriented single-crystalline LaAlO 3 film with a rocking curve of 0.15° and no secondary phases. The use of SrTiO 3 buffer layers on silicon allows perovskite oxides which otherwise would be incompatible with silicon to be integrated onto a silicon platform.