THE THERAPY of the medicinal plants has always been a part of our environment as they have several therapeutic virtues. These properties are generally attributed to secondary metabolites such as polyphenols. In this study we investigated the three extracts; ethyl acetate, methanolic and water extract of the leaves of Acacia saligna (Wendl H. L.) which is used traditionally in the treatment of various diseases. They were assayed against Gram-positive bacteria (Staphylococcus aureus, Staphylococcus pyogens, Bacillus cereus, Bacillus subtilis), Gram-negative bacteria (Escherichia coli), fungi and yeast (Candida albicans) using the diffusion and serial methods. The susceptibility of the microorganisms to the extracts of these plants was compared with each other and with selected antibiotics whereby the ethyl acetate extract being the most effective. The active ethyl acetate extract was phytochemicaly studied as well for their polyphenolic constituents, where they afforded sixteen polyphenolic compounds among which two different phenolic acids, two catechins and seven flavonoids were isolated for the first time from A. saligna. The structure of all the isolated compounds was elucidated on the basis of spectral analysis.