A novel inherently conducting polymer, high-quality polyfluoranthene (PFA) film with electrical conductivity of 10(-2) S cm(-1), was first synthesized electrochemically by direct anodic oxidation of fluoranthene in a middle strong Lewis acid-boron trifluoride diethyl etherate. The oxidation potential onset of fluoranthene in this medium was measured to be only 1.07 V vs SCE, which was much lower than that in acetonitrile + 0. 1 mol L-1 tetrabutylammonium tetrafluoroborate (1.68 V vs SCE). This PFA film showed good redox activity and stability even in concentrated sulfuric acid. Moreover. the fluorescence properties of PFA were greatly improved in comparison with those of the monomer. Dedoped PFA films were partly soluble in polar solvents such as CH2Cl2, acetone, tetrahedrofuran, and dimethyl sulfoxide. The structure and morphology of the polymer were investigated by UV-vis spectroscopy, infrared spectroscopy, and scanning electron microscopy, respectively. The results of quantum chemistry calculations of fluoranthene monomer and H-1 NMR spectroscopy of dedoped PFA films indicated that the polymerization mainly occurred at C-(3), C-(4) C-(13), and C-(14) positions.