Myrtaceae family vegetables have in their constitution essential macro and micronutrients and bioactive compounds that can have biological effects, for instance, antimicrobial and antioxidant activity. The natural antimicrobial systems present in plants, animals or microorganisms are gaining increasing space in the context of alternative conservation of food products, and the use of plant extracts has been highlighted in research. Therefore, in the present work, the antimicrobial activity of Syzygium mallancences extracts was evaluated aiming its application as a supporting agent in food preservation. The leaves were collected, processed and dehydrated (35±2°C for 48h), and then submitted to extraction processes through the techniques of maceration, infusion and decoction. The supernatants obtained after the extractions were lyophilized and stored under refrigeration at -18°C. The antimicrobial potential of the extracts was analyzed using the agar well diffusion methodology on Escherichia coli ATCC 25922 strains, Salmonella Enteritidis IAL 1132, Listeria monocytogenes ATCC 19115 and Staphylococcus aureus ATCC 27664. The aqueous extracts were tested in duplicate at concentrations of 100, 50 and 25 mg/ml. The positive control of antibiotics tested was amikacin and gentamicin (10µg/50µL). The samples did not show substantial sensitivity to gram-negative microorganisms, possibly due to the structural complexity of their cell wall, whereas to gram- positives, activity was only found at the highest concentration tested (100 mg/ml), for the three extracts evaluated. The aqueous extract obtained by the infusion method showed better inhibitory action in contrast to gram-positive bacteria with halos between 18 and 17 mm, while the others remained between 13 and 17 mm. Based on the above considerations, it is concluded that the infusion extract was the one that presented the greatest potential for possible use as an adjunct in food preservation.