The study on the survey and identification of traditional medicinal plants in Arsi Suderndistrict was performedfrom October 2015 to February 2016 in three kebeles Gojamarnnegele, Yabeta kula and Akiya meti. In the area diverse medicinal plant species which arernused to treat many human and livestock disease have been documented.The data wererncollected from the informants through semi-structured interview, discussion and collectingrnplant samples from the study areas that are used to treat different human and livestockrnailments. A total of 21 informants were selected that consist of seven informants fromrneach kebele of which 16 were males and five females. Among the informants six of themrnwere key informants selected by purposive sampling method. A total of 36 medicinal plantrnspecies were collected from the study area and identified using the Flora of Ethiopia andrnEritrea (volume 3, 1989). The medicinal plant collected are used to treat six diseaserncategories. Namely, dermatological, respiratory, ureno-genital, gastro-intestinal, febrile andrnlivestock disease. The frequently applied plant part was leaf (58%) followed by root (25%).rnTraditional healers commonly used the juice of fresh leaf and root of medicinal plants.Tornprepar it fresh part of the plant is crushed and the juice applied orally, nasally or dermally.rnHowever; these plant species are threatened by the activities of the community likernexpansion of agriculture, overgrazing, cultivation of eucalyptus tree as cash plant andrnapplication of the root of medicinal plant is a factor that needs risk of extniction.rnTo conserve the biodiversity of the area and preserve the medicinal plants it isrnrecommended to make aware of the society and to develop in â€“situ and ex-siturnconservation of medicinal plants.rnKey word; Traditional medicinal plants, traditional healer, Human diseases, Livestockrnailments.