An amperometric biosensor for the quantitative measurement of ethanol is reported. The biosensor is based on a biocomposite that is robust, polishable and easily mechanised. This biocomposite is made of graphite powder, an epoxy resin and the enzyme alcohol oxidase. The enzyme is stable in the biocomposite matrix for more than three months. The biosensor is sensitive to several alcohols but ethanol has been chosen as the analyte for the characterisation and evaluation of the biosensor. Hydrogen peroxide produced by the enzyme reaction is oxidised electrochemically at a potential of 1100 mV vs Ag/AgCl. The electrochemical medium used was a 0.1 M phosphate and 0.1 M KCl aqueous solution buffered at pH 7.00. The linear range of the response was between 0.5 and 29 mg/ml. © 1998 Elsevier Science Ltd. All rights reserved.