Hibiscus diversifolius which is widely distributed in Kenya was investigated for its antibacterial effect against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus. The leaves stem and root of the plant was extracted using aqueous and methanol as solvents. Phytochemical screening was also carried out to determine the phytochemical constituents present in the various parts of the plants used. The results show that both aqueous and methanolic extracts of the different plant parts had antibacterial activity against the various microbes tested. Phytochemical screening revealed the presence of alkaloids, flavonoids, sterols, saponins, terpenoids and cardiac glycosides while tannins and steroids were lacking in all the extracts.