Abstract: Twelve preparation of the ethanol and water extracts of four medicinal plants,Anogeissus leiocarpus(root and bark), Terminalia glaucescens(root and bark), Adansonia digitata(bark) and Lennea welwitschii(bark) were screened for their inhibitory effect on Escherichia coli, Salmonella typhii, Staphylococcus aureus and Shigella dysentriae using the agar-diffusion method. The efficacy of the extracts was assessed by measuring the diameter of zone of inhibition around the colonies on nutrient agar medium. The result obtained showed that the ethanol extracts (root) from T. glaucenscens and A. leiocarpus were active against all the test bacteria. The ethanol and aqueous extracts of A. digitata did not exert any inhibitory effect on test organisms, while the other eight extracts exhibited variable antibacterial activities.