The effective biaxial modulus (M-eff) and strain energy density (W/epsilon(2)(parallel to)) of hexagonal, tetragonal and orthorhombic polycrystalline films with ideally (h k l) fiber textures are evaluated using the Vook-Witt, inverse Vook-Witt, Voigt, Reuss and Voigt-Reuss-Hill grain interaction models. A two-dimensional Dirac delta function is employed to describe the orientation distribution function of these films. Numerical results show that the averages of M-eff calculated with the five models are identical for the (0 0 1) plane of ideally fiber-textured hexagonal and tetragonal films. The evolution of M-eff with Euler angle theta(c) indicates that M-eff of hexagonal films is related to theta(c) only. However, tetragonal and orthorhombic films represent various M-eff even if theta(c) is uniform, which implies that both theta(c) and phi(c) contribute to the change of M-eff. (C) 2008 Elsevier B. V. All rights reserved.