The effect of ethanol on the surface-enhanced Raman scattering (SERS) of water molecules in a 0.5 M KCl-water-silver electrode system was studied by observing changes in the SERS band of water as a function of the time of ethanol addition during the oxidation-reduction cycle. Hydrogen bond breaking, the main role of ethanol, in the SERS system of water-ethanol seems to be a necessary condition but not a sufficient condition for observing SERS of water. Surface adatoms of Ag-0-Cl- should also be available at the time of the hydrogen band breaking by ethanol mixing.