Medicinal plants are playing remarkable role in primary health care of human in developing countries in general and Ethiopia in particular. The study was carried out to document the indigenous knowledge and medicinal plants in and around Ambo town. It was carried out from April 2018 to August 2018. Forty nine (49) informants were selected from the representative kebeles (small administrative units) randomly using lottery method. Twenty two traditional medicinal plants were identified and documented based on their usage in traditional medicine to treat different human diseases. The Euphorbiaceae Family is represented by highest number of species of all plants followed by Asteraceae. The declining number of medicinal plant is one of the causes for the losses of the associated knowledge of the medicinal plants. Traditional knowledge of medicinal plants uses and management is owned by people of the study area and need to be integrated to modern school.