Iron complexed with dimethylacetamide (DMAc) was incorporated in variable ultra low concentration in polyimide (PI) at it precursor stage to obtain nanoscopically manipulated metallopolyimide films. The in situ generation of these nanophase structures, their stability within PI matrix, and interaction with its chains was studied using UV-vis spectroscopy. AFM topographic image shows the presence of rock-shaped nano particles, which is produced by the formation of polyamic acid salt of Fe-DMAc complex. Unique fluorescence and improved hydrolytic stability of these metallopolyimide films were due to the formation of nanophase structures. Different photo-physical properties of developed films are attributed to size quantization effect. POLYM. ENG. SCI., 49:977-983, 2009. (C) 2009 Society of Plastics Engineers