Leaves extracts of Syzygium cumini (L) were collected to test their antimicrobial activity. The collected materials were extracted by petroleum ether, methanol and water by using different concentration (15% 10% and 5%). Were obtained and bioassay in vitro for its bioactivity to inhabit the growth of four types of bacteria,namely; (Staphlococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Bacillus subitils) and two types of fungi (Aspergillus niger, and Candida albicans). The extract of Syzygium cumini leaves showed different activity against the selected bacteria at all concentration levels. By using cup plate diffusion method, petroleum ether extract of Syzygium cumini leaves showed activity against E. coli only. Methanol extract showed variable activity against bacteria in different concentrations especially 15% concentration showed high activity against B. subtilis. Water extract showed variable activity against most of the tested bacteria. E. coli was found to be sensitive to all concentrations.