Titania-containing polyimide (PI) hybrid films with homogeneous and flexible properties have been fabricated via sol-gel process. Various contents of titania are added to three different PI systems by using acetylacetone to reduce the reaction rate and to prohibit gelation. The thermal, electrical and mechanical properties of the hybrid films will be measured and compared to pure PI. Results indicate that the metal-containing PI possesses lower thermal expansion and resistivity than pure PI. Incorporation of small amount of titania enhances mechanical properties of the hybrid films at both low and elevated temperature. The relationship between the effect of titania concentration, structure and properties will also be discussed. (C) 2003 Elsevier B.V. All rights reserved.