Aims: To evaluate the disinfection effectiveness of slightly acidic electrolysed water (SAEW, pH 6.25-6.53), a new environmental friendly agent for inactivating micro-organisms adhered to the facility and aerosolized in the air of the swine barns and to explore the application of SAEW in livestock industries. Methods and Results: Bacteria and fungi were isolated from the swine house air and treated by SAEW. The SAEW solution was flushed onto surfaces and sprayed within the whole swine barn. SAEW with an available chlorine concentration (ACC) of 300mgl(-1) can inhibit isolated microbes completely. The usage of SAEW (300mgl(-1)) resulted in a significant (P<0.05) reduction in microbes on the wall, rail and floor after flushing disinfection. Additionally, spraying SAEW at an ACC of 300mgl(-1) reduced 59% of the airborne organisms in 30min and kept the population of microbes at a reduced level for at least 8h. SAEW treatment also reduced pathogens on surfaces (P<0.03) after spraying disinfection except on the surface of the wall. Conclusions: SAEW may be a potential alternative disinfectant to reduce infections in swine barns. Significance and Impact of the Study: The results of this study provide information on the antimicrobial efficiency of SAEW on the airborne bacteria and fungi in swine barns.