The Psidium guajava L. specie is a perennial shrub, belonging to the Myrtaceae family and it is popularly known as guava, its leaves are used in therapy for treating various diseases. The study aims to evaluate the antibacterial activity in vitro of manipulated product obtained from dried extract of the leaves of P. guajava L. front standard bacteria ATCC and clinical isolates. The tests were conducted on bacterial samples: Staphylococcus aureus (ATCC 25923), Pseudomonas aeruginosa (ATCC 27883), Escherichia coli (ATCC 25922), Salmonella spp, Acinetobacter baumannii, Proteus mirabilis, Shigella flexneri, Staphylococcus epidermidis, Staphylococcus haemolyticus, Streptococcus agalactiae, Streptococcus mutans. Among the tests can be mentioned phytochemical of the P. guajava leaves ethanolic extract (EE), microbiological control and physical-chemical analysis of the product and microbiological tests such as agar diffusion method (wells), minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), an evaluation test of hemolytic capacity of the solution and in vitro assay cytotoxic activity were performed, . The best result of the product in the agar diffusion method was front Staphylococcus epidermidis, while the lower MIC and MBC were front Staphylococcus aureus (ATCC 25923). The product showed no hemolytic activity and no cytotoxic activity at the tested concentrations. According to the test results, it is believed on the possibility of the production of a pharmaceutical formulation derived from the dry extract of Psidium guajava, since it showed great antibacterial activity.