Acetylene was electrochemically polymerized cathodically at -0.60 V (versus Ag/AgCl) in the presence of copper(I)perchlorate catalyst in acetonitrile containing tetrabutylammonium perchlorate (TBAP) at room temperature under nitrogen atmosphere. An insoluble, black film was deposited on platinum (Pt) and copper (Cu) working electrodes. The dry electrical conductivity of the fresh film was about 550 S cm(-1). The chemical structure of the product was investigated by cyclic voltammetry, infrared spectroscopy (IR) and atomic absorption spectroscopy (AAS). Based on the IR data the product consists of a cis-rich form of polyacetylene. (C) 2002 Elsevier Science B.V. All rights reserved.