There have been reports of increasing development of drug resistance among human pathogens as well as undesirable side effects of certain antimicrobial agents.It is therefore necessary to search for new agents that are better, cheaper and without side effects for treating infectious diseases especially in developing countries. In this study, phytochemical composition and antimicrobial activities of aqueous and ethanolic extracts of leaves of Mangifera indica were investigated. Standard methods were employed to screen for the phytochemicals. Agar well diffusion method was used to determine the antimicrobial effects of aqueous and ethanolic extracts of M. indica leaves against seven different clinical isolates namely:Stapylococcus aureus, Micrococcus virians, M. leteus, Escherichia coli, Klebsellia pneumoniae, Pseudomonas aeruginosa and a fungus, Candida albicans. Phytochemical screening showed the presence of active pharmacological components such as tannins, saponins, cardiac glycoside, flavonoid and alkaloids. Aqueous extract demonstrated a higher activity than the ethanolic extract. S. aureus showed highest sensitivity to the aqueous extracts with MIC 31.25mg/mL. Least sensitivity was observed in K. pneumoniae and Candida albicans with MIC 125mg/mL each in the two extracts.M. indica exhibited significant antimicrobial activity comparable to gentamicin which is used as control in this study.