Abstract We have first found the way to obtain a uniform and flexible polyparaphenylene (PPP) film by electrochemical polymerization of benzene in concentrated sulphuric acid with an anhydrous Lewis acid as catalyst. It is evident that concentrated sulphuric acid plays an important role in the electrochemical polymerization of benzene. It protonates benzene into benzenium. The rotation of the working electrode is an important condition for obtaining uniform and flexible PPP films. The thickness of the PPP film can be controlled by the electricity used for polymerization and the amounts and kinds of catalysts employed. The colour of the PPP film changes from transparent yellow to black, depending on the thickness. The PPP film is electroactive in concentrated sulphuric acid. The stable polymer film (PPP) is a suitable underlayer for polyacrylamine (PAA) formation by the electrochemical polymerization method. This PPP/PAA film has high potential for applications in the extraction of trace metal ions, ion exchange and in catalysis.