Plants are indispensible sources of medicinal agents for thousands of years and an impressive number of modern drugs have been isolated from the natural sources. Calotropis gigantea, Leucas aspera and Euphorbia hirta are abundantly available weed plants. The present study states that evaluation of “antibacterial effect” on comparison to that of individual extracts and formulated extracts. The effect of cytotoxicity against the bacteria was analysed for individual plant extracts such as Calotropis gigantea (E1), Leucas aspera (E2), Euphorbia hirta (E3) and formulated plant extract in the ratio of 1:1:1. The leaf extract of three weed plants were performed by solvent extraction method. The antibacterial activity was done by disc diffusion method using different concentration (10, 20, 30, 40, 50μL). The DPPH assay was done to analyze the antioxidant effect. It was concluded that the combinational study has given the highest cytotoxic effect against bacterial infections than the individual extracts