Abstract High quality free-standing poly(9-fluorenone) (PFO) films were synthesized electrochemically by direct anodic oxidation of 9-fluorenone (FO) in pure boron trifluoride diethyl etherate (BFEE). The oxidation potential of FO in this medium was measured to be only 1.48 V versus SCE, which was greatly lower than that determined in CH 2Cl 2 + 0.1 mol l −1 Bu 4NBF 4 (2.21 V versus SCE). PFO films obtained from BFEE showed good electrochemical behavior, good thermal stability with electrical conductivity of 7.8 × 10 −3 S cm −1, indicating that BFEE was a better medium than CH 2Cl 2 for the electrosyntheses of PFO films. Structural studies showed that the polymerization of FO ring occurred at 2,7-position. As-formed PFO films can be partly dissolved in acetone and tetrahydrofuran (THF). Fluorescent spectral studies indicate that PFO is a good blue light emitter. To the best of our knowledge, this is the first report on the electrosyntheses of free-standing PFO films.