Thiophene, bithiophene and terthiophene have been electropolymerised using ionic liquids as the growth medium and the supporting electrolyte. Both imidazolium and pyrrolidinium-based ionic liquids were used to assess the influence of the nature of the ionic liquid on the morphology and electrochemical activity of the conducting polymers. The pyrrolidinium-based ionic liquid produced slightly smoother films for all the thiophene species studied. A number of the polymers displayed multiple redox peaks, the possible origins of which are discussed. Both the ionic liquid and the choice of monomer had a significant influence on the polymer produced. (c) 2005 Elsevier Ltd. All rights reserved.