Electrolyzed water(EW) can be produced by electrolysis of a dilute salt solution. Slightly acidic electrolyzed water(SAEW, p H 5.0–6.5) and neutral electrolyzed water(NEW, p H 6.5–8.5) are considered healthy and environmentally friendly because no hazardous chemicals are added in its production, there is reduced corrosion of surfaces and it minimizes the potential for damage to animal and human health. Over the last decade, EW has become increasingly popular as an alternative disinfectant for decontamination in animal houses. However, there have been some issues related to EW that are not well known, including different mechanisms for generation of SAEW and NEW, and the antimicrobial mechanism of EW. This review covers the definitions of SAEW and NEW, different generation systems for SAEW and NEW, the antimicrobial mechanism of EW, and recent developments related to the application of SAEW and NEW in animal houses.