Production of very thick polypyrrole films is an easy process, as the thickness can be controlled in a galvanostatic experiment by measuring the polymerization time. When using the p-toluene sulfonate anion, tough and flexible films with a high specific conductivity (70–90 O-1 cm-1) are produced. These properties are the same for films, produced in both acetonitrile and aqueous solutions. Both types of films contain a large amount of incorporated anion and solvent, even after drying in vacuo at room temperature. In aqueous solutions a polymer film with tube-like bulges are formed, probably caused by a spiralled microstructure of the chain. In acetonitrile no such tubes are found.