An intercalation process was used to prepare polyimide-clay nanocomposite films from the polyimide precursors (PMDA-ODA) and organo-modified clay in N,N-dimethylacetamide. The structure of the films was characterized by X-ray diffraction and transmission electron microscope techniques. The dielectric and dynamic mechanical properties of the films were studied over broad temperature and frequency ranges. The dependences of dielectric constant, dielectric loss, storage modulus and mechanical loss factor on the clay content, temperature and frequency in the films were discussed. The films with a proper amount of clay displayed relatively low dielectric constant compared to the pure polyimide film and a high glass transition temperature. (C) 2004 Elsevier B.V. All rights reserved.