Diarrhoea, particularly infectious diarrhoea in children less than 5 yrs of age is labeled as the second leading cause of mortality and morbidity throughout the world. since the majority of the people who lives in these developing countries have no access for modern treatment, it has made them to look for other alternative therapies such as, the use of medicinal plants. Ethiopia is one of the well known countries of the world where medicinal plants are used widely.The major objective of the study is to evaluate the antibacterial activity of three medicinal plants (Gardinea lutea, Olea europaea subsp. cuspidata, Myrica salisfolia) against clinical isolates of Shigella and Salmonella and a control strain E. coli ATCC (25922).