This investigation was carriedout between 2013-2016 in five districts of SNNPR (Anlemo, Duna, Gibe, Gombora and Yem) with the objective of documenting and analyzing traditional medicinal plants (MPs) and the health care knowledge of the society. Vegetation data were gathered from 123 quadrats each 30x30 m laid in different land use types in the districts. Clustering was undertaken to identify plant communities, Shannon-Weiner Index was calculated to evaluate the diversity of species, Sorensonâ€™s coefficient was calculated to assess similarity in species, and ordination was performed to identify the effects of environmental factors plant communities. Ethnobotanical data were gathered from 399 general and 102 key informants through individual interviews, focus group discussions, participant observation, market surveys and guided transect walk. Quantitative ethnobotanical tools including Preference Ranking, Direct Matrix Ranking, Informant Consensus Factor, Fidelity Level, Use Value, Relative Impotrance and Use Diversity indices were calculated to identify most culturally important MPs. A total of 468 species of vascular plants were recorded from vegetation data. Five plant communities were identified in Hadiya and three in Yem. The communities had diversity indices between 3.35-4.89 and evenness 0.87-0.97. Monte Carlo test showed that altitude, slope, aspect and disturbance in Yem, and three of the former in Hadiya had significant effects on the distribution of plant communities (p