Electrochemical degradation of trichloroethylene (TCE) was studied by flow-through electrolysis in acetonitrile (AN). TCE was electrolyzed to acetylene in a quantitative yield at a composite electrode consisting of stainless steel (SS) and oxidatively pretreated glassy carbon (GCO) particles. On the GCO particle TCE was reduced to intermediate C2HCl, which was further reduced to C2H2 on the SS particle. Although SS was not active for TCE reduction, SS displayed higher activity for the reduction of C2HCl than GCO. The activity of SS was attributed mainly to Ni and Cr atoms at the SS surface, but SS demonstrated higher activity than Ni and Cr in H2O-AN media. At potentials below -2.1 V vs. Ag10 mM Ag+(AN), TCE in 1% H2O + AN was converted to C2H2 in a 100% yield.