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We have used transmission electron microscopy and characterized the microstructure in thin films of La1-xTexMnO3 (x = 0.1, 0.2) compounds, which are new additions to the family of colossal magnetoresistance (CMR) oxides. Electron diffraction and high-resolution imaging reveal that Te-doped thin films with a thickness of 100 nm for x = 0.1 and 200 nm for x = 0.2 are epitaxially grown on the SrTiO3 (001) substrate. On the basis of electron diffraction patterns obtained from cross-section and plan-view specimens, the new compounds are determined to have an orthorhombic unit cell with lattice parameters a(o) approximate to 2(1/2) a(p) = 0.54 nm, b(o) approximate to 2a(p) = 0.77 nm, c(o) approximate to 2(1/2) a(p) = 0.54 nm, where a(p) is the lattice parameter of an ideal cubic perovskite structure, 0.39 nm. The microstructures in orthorhombic La1-xTexMnO3 compounds are clarified in terms of two 90degrees-oriented domains, both of which are grown with [101] axis perpendicular to the substrate surface. (C) 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.