Couroupita guianensis Aubl and Erythroxylum monogynum Roxb. are medicinal plants popularly used in traditional medicine to cure many ailments. The aims of this research were to screen the extracts of the leaves of the two medicinal plants for phytoconstituents, and to approve the antibacterial property of the extracts against four strains of bacterial species, namely, Escherchia coli, Klebsiela pneumoniae, Pseudomonas putida and Staphylococcus aureus. The highest inhibition zone noted for aqueous extract of E.monogynum leaves against E.coli was 14.66 mm followed by ethanol extract (13.80 mm). The highest activity of acetone extract against K.pneumoniae was (12.0 mm). The ethanol leaf extracts of C.guianensis showed maximum antibacterial activity against E.coli (13.60 mm). The acetone leaf extracts showed highest activity against P.putida (12.80 mm). The aqueous leaf extracts showed significant activity against E.coli (12.28 mm). The results of the phytochemical screening various solvent namely acetone and methanol were taken which revealed that the leaves extract of C.guianensis contained tannins, saponins, flavonoids, terpenoids, phytosterols, cardiac glycosides and carbohydrates. Phytochemical analysis of E.monogynum showed the presence of saponins, tannins, flavonoids and alkaloids. In conclusion, the present results of the study evidence the utilize of the plants in traditional biomedicine for the curing of ailments caused by the microorganisms.