A new approach for predicting effective elastic moduli of microscopically inhomogeneous and anisotropic polycrystalline materials is proposed in the present paper. The expression of the proposed approach is exhibited in a form of geometric mean value of Reuss and Voigt tensors for effective elastic moduli of inhomogeneous and anisotropic polycrystalline materials and therefore unique. Predictions of elastic moduli for Cu and α-Fe polycrystals using the present approach are made and compared to those of Hill and Kroner. The results are promising.