Two new noncentrosymmetric (NCS) polar oxides, BaMgTe2O7 and BaZnTe2O7, have been synthesized and characterized, with their crystal structures determined by single crystal X-ray diffraction. The iso-structural materials exhibit structures consisting of layers of corner-shared MgO5 or ZnO5, Te6+O6, and Te4+O4 polyhedra that are separated by Ba2+ cations. The Te4+ cation is found in a highly asymmetric and polar coordination environment attributable to its stereoactive lone-pair. The alignment of the individual TeO4 polar polyhedra results in macroscopic polarity for BaMgTe2O7 and BaZnTe2O7. Powder second-harmonic generation (SHG) measurements revealed a moderate SHG efficiency of approximately 5 X 1(DP (or 200 X alpha-SiO2) for both materials. Piezoelectric charge constants of 70 and 57 pm/V, and pyroelectric coefficients of -18 and -10 mu C.m(-2).K-1 were obtained for BaMgTe2O7 and BaZnTe2O7, respectively. Although the materials are polar, frequency dependent polarization measurements indicated that the materials are not ferroelectric, that is, the observed macroscopic polarization cannot be reversed. Infrared, UV-vis diffuse spectroscopy, and thermal properties were also measured. Crystal data: BaMgTe2O7, orthorhombic, space group Ama2 (No. 40), a = 5.558(2) angstrom, b = 15.215(6) angstrom, c = 7.307(3) angstrom, V = 617.9(4) angstrom(3), and Z = 4; BaZnTe2O7, orthorhombic, space group Ama2 (No. 40), a = 5.5498(4) angstrom, b = 15.3161(11) angstrom, c = 7.3098(5) angstrom, V = 621.34(8) angstrom(3), and Z = 4.