An ethnobotanical study of medicinal plants used by local people of Wayu Tuka Wereda wasrncarried out from September 2009 to June 2010. The study focused on the investigation of therntraditional uses of various plants, of the study area. The data were gathered from indigenousrnpeople, local healers and knowledgeable elders of the study area. A total of 63 informants (41rnmale and 22 female) aged between 19-102 years were randomly selected from nine Kebeles.rnRelevant information were collected by using semi-structured interview, market survey, fieldrnobservation and discussion. Preference ranking, paired comparison, and direct matrix rankingrnwere used for data analysis. Based on visual classification, 6 communities were identified;rnnatural and the other 3 from homegardens. Out of the 202, 126 were studied for their medicinalrnuses. Medicinal plant species are distributed in 108 genera and 56 families. Fabaceae consistedrnof 15 species while Solanaceae, were recorded 8 species. A large number of medicinal plantsrnwas collected from natural habitat 86(68%), whereas 33(26%) from homegardens and 7(5.5%)rnoccur both in the homegardens and natural habitat. About 78(62%) of medicinal plants werernreported for treatment of human, while 23 (18.2%) were for livestock ailments. In addition,rn25(20%) were reported for treatment of both human and livestock ailments. In the study area,rnleaves (43%) and roots (18.5%) were the two frequently utilized plant parts for preparation ofrnremedies. Crushing which accounted for 29% was a widely used method of preparation ofrntraditional medicine in the study area. This is followed by powdering (28%) whereas; largernnumbers of the medicinal plants were cited to be used in fresh form, few were used dry. The mostrncommon mode of administration was found to be oral (64%). Analysis of preference rankingrnshowed, Acmella caulirhiza was the most preferred medicinal plant by people of the study arearnto treat tonsillitis. Paired comparison showed that Cucumis ficifolius was found to be the mostrnpreferred plant to treat blackleg. Some medicinal plants are popular than others in treatingrnvarious diseases. For instance, Allium sativum and Ocimum urticifolium were found to be thernmost popular since each medicinal plant was reported 55 times (8 %.). Concerning informantrnconsensus factor, the highest ICF values were linked to problems associated with Malaria andrnHeadache (0.85) followed by Fibril illness, Swelling and Evil eye (0.79). The lowest ICF valuernwas linked with Rabies (0.25). Deforestation (agricultural expansion, construction and woodrnmaterial for fire) urbanization and over collection were reported to be the major threats tornmedicinal plants. In addition, the apparent disinterest of the young generation in traditionalrnmedicine has become a profound problem for the continuity of the knowledge of medicinalrnplants. The effort of local people in conserving medicinal plants is minimal since much ofrnmedicinal plants have been gathered from the wild. To tackle the depletion of knowledge fromrnever loss, awareness of young generation on the usage of traditional medicine is recommended.rnKey words: Conservation, Deforestation, Ethnobotany, Medicinal plants Traditionalrnmedicine, Wayu Tuka Wereda