One crucial stage in the hunt for new compounds with potential applications in medicine is the screening of medicinal plants for antimicrobial activity. The present study was carried out at the Botany Department's Phytochemistry Lab at Hazara University Mansehra. The leaves of the species Aerva javanica were gathered in District Mardan. The Agar Well-Diffusion method was used to assess the antibacterial activity, and the zones of inhibition were expressed in millimetres. The following four microbial strains were employed: Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The positive control in this experiment was vancomycine. The maximal inhibition zone of Aerva javanica methanolic extract against Staphylococcus aureus was 21 mm, whereas the minimum inhibition zone against Escherichia coli was 15 mm. In order to identify the active bands, the plant crude extract was subsequently put via bioautography. It was evident that both plant bands exhibited strong antibacterial activity due to their high Rf values. To investigate the biofilm production of crude plant extract, the Pellicle Assay was carried out in test tubes. The same four bacterial strains were combated with a crude plant extract. While plants and broth media are found in the negative control test tube, bacteria and broth media are present in the positive control test tube. Key word: Anti-microbial activity of leave extract and inhibition of pellicle formation of Aerva javanica.