Heteroepitaxial growth of ultrathin (5-40 angstrom) aluminum oxide films was successfully carried out on a Ta(110) substrate between 700 and 900 K by means of vacuum reactive deposition. Low-energy electron diffraction (LEED) indicated the formation of a long-range ordered epitaxial Al2O3 film with a slightly distorted (beta = 117.9) hexagonal lattice corresponding to close-packing of oxygen (O2-) anions. The epitaxial overlayer was found to exhibit a Kurdjumov-Sachs (KS) type orientational relationship with respect to the Ta(110) substrate with approximately 4.2-degrees rotational mismatch.