Electrochemically activated (ECA) water is being extensively studied and considered as an alternative to chlorine for disinfection. Some researchers claim that ECA is by and large a chlorine solution, while others claim the presence of reactive oxygen species such as ozone and hydroxyl radicals in addition to chlorine. This study compares sodium hypochlorite (NaOCI) and ECA in terms of disinfection efficacy, trihalomethanes (THMs) formation, stability and composition. The stu(jies were carried out under different process conditions (pH 5,7 and 9, disinfectant concentrations of 2-5 mg/L and dissolved organic carbon (DOC) concentration of 2-4 mg/L). The results indicated that in the presence of low DOC {<2 mg/L) ECA showed better disinfection efficacy for EscheriMa colt inactivation, formed lower THM and had better stability compared with NaOCI at both pH 5 and 7.Stability studies of stock solutions showed that over a period of 30 days, ECA decayed by only 5% while NaOCI decayed by 37.5% at temperatures of 4 °C. In a fresh ECA of 200 mg/L chlorine, about 5.3 mg/L ozone and 36.9 mg/L CIO2 were detected. The study demonstrates that ECA could be a suitable alternative to NaOCI where decentralized production and use are required.