Acidic electrolyzed water (EW) (pH 2.6-5.8) and alkaline EW (pH 11.2-12.1) were examined as potential disinfectants against foot-and-mouth disease virus (FMDV). Using acidic EW with pH 2.6 and alkaline EW with pH >11.7, the viral titer decreased in vitro by > 4.0 log values, 2 min after the virus was mixed with EW at a 1:10 dilution. The strong virucidal effect of acidic EW (pH 2.6), but not that of alkaline EW (>11.7), seemed to depend on the chlorine level in the solution. Genetic analysis revealed that viral RNA was substantially reduced, especially by alkaline EW.