The purpose of the study was to determine the antibacterial activity of the cold and hot water extract of the Mangifera indica, Morinda citrifolia and Syzygium cumini leaves by agar well diffusion method. Among the plant extracts that showed the best antibacterial activity was further used to evaluate the colony count reduction of plant extracts after application on the floor surfaces and to analyse the phytochemical present. The study showed that hot water extracts of S.cumini leaves showed the best antibacterial activities against all the test organisms and it was also observed that the number of microorganisms reduced significantly after application on the floor surfaces. The phytochemical analysis of hot water extract of S.cumini leaves showed the presence of tannin, flavonoids, terpenoids, saponin, phenol but absence of alkaloids. Thus, hot water extract of S.cumini leaves can be selected as the best plant extract for plant-based disinfecting agent among the other plant extracts. This is the first report for hot water extract of S.cumini leaves which is tested for efficacy of plant-based disinfecting agent.