Galactose oxidase has been immobilized in a polyaniline film. The response current of the galactose oxidase electrode is a function of the applied potential and increases as the pH increases from 5.61 to 7.25. The optimum pH of the immobilized galactose oxidase is 7.25. The activation energy of the enzyme-catalysed reaction is 41.8 kJ mol-1. The response current of the enzyme electrode shows good reproducibility at temperatures below the optimum temperature of 30.4-degrees-C and increases as the galactose concentration increases from 0.2 to 6 mmol dm-3. Thus the polyaniline galactose oxidase electrode can be used to determine galactose concentration.