This study screened the variation of phytochemicals in Terminalia brownii leaves, bark and root extracts and evaluated their microbial activity against Escherichia coli and Staphylococcus aureus. Preliminary phytochemical screening showed the presence of tannins, alkaloids, saponins and steroids in leaves, bark and roots; terpenoids in barks and roots, while flavonoids were absent. Leaf, bark and root extracts significantly (p ˂0.05) inhibited E. coli and S. aureus growth. Root extracts (methanol and ethanol) had significantly higher zones of inhibition (18.0 and 14.6 mm) against E. coli compared to the other plant parts. Similarly, leaf and root extracts produced higher zones of inhibition of 12.3 and 17.4 mm against S. aureus, respectively. Data from this study shows that T. brownii is a good candidate for further pharmaceutical investigations and could be exploited for the development of natural bioactive agents to improve human health.