Mirabilis jalapa is a medicinal plant which belongs to the family Nyctaginaceae, commonly called the four o’clock flowering plant or marvel of peru, which is the most commonly grown ornamental plant and is native to tropical South America, and introduced in North America, mainly in southern, eastern and western states. However there are some disagreements about where it came from originally: Mexico, Chile and India. It was officially botanically recorded in the year 1753, although it has been long distributed as ornamental plant through the tropics of the world it is a popular garden ornamental in southern climate zones, where it grows rapidly and bears flowers that open in late afternoon, hence the common name. It is been used as folklore remedies around the world. The present study was carried out to explore the protein content, phytochemical constituents and antimicrobial properties of Mirabilis jalapa against eight both gram negative and positive test organisms in comparison with standard antibiotics streptomycin. The result reveal that the leaf extract of Mirabilis jalapa has high amount of protein content and also has very good anti-microbial activity against both gram negative and gram positive organism when compared to standard antibiotics streptomycin. The ethanol extract has shown significant activity against all the organisms but rather more towards Shigella dysenteriae, followed by Escherichia coli, Lacidophilus, klebsiella pneumonia, Pseudomonas and Staphylococcus aureus. Similarly, petroleum ether, chloroform, and aqueous extract of plant also showed good inhibition against Vibro cholera followed by Pseudomonas, Staphylococcus aureus. This indicates that the leaf extract of Mirabilis jalapa has potential antimicrobial activity with concentration dependent and can fight against these organisms and could be a good substitute to the contemporary medicines.