The conventional antimicrobial technique was based either on poisons or heavy metals, which may not killed the microbes completely, allowing the microbe to survive, change, and become resistant to the poisons and/or heavy metals. Hence, the identification and evaluation of new antimicrobial agents are inevitable. The medicinally important plants, Camellia sinensis (green tea), cuminum cyminum (cumin), Cinnamomum cassia (cinnamon) were taken for the present study. The aqueous extracts of these plants were used in different concentrations (0.5g, 0.25g, 0.12g / 2 ml) against four pathogenic strains namely Escherichia coil, Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa. Antibacterial activities of different extracts were evaluated by well diffusion method. Ampicillin, Ciprofloxacin were used as standard drugs. The aqueous extracts of all three plants showed significant antimicrobial activity against the selected microorganisms when compared to the standard drugs. The green tea showed the maximum zone of inhibition against the organisms used in the present study. Camellia sinensis (Green tea) could be used as an antimicrobial agent against the E.coli, S.aures, B.subtilis and P.aeruginosa.