Historically, development in Ethiopia, is a result of intimate highland-lowland interdependencies and complementarities. However, over the course of time, this age-old equilibrium that has harmoniously ruled the economic, social and political life of the highland and lowland communities is getting weaker. This study aimed at investigating the nature and extent of links between the highland and lowland communities of Bale administrative zone and the consequent impacts on their livelihoods. Multi-stage cluster sampling techniques were employed to select 403 sample household heads from the two agro-ecological regions. Questionnaire, interview, FGD and field observations were used as tools of primary data collection. ANOVA, multiple linear regressions ans binary logistic regression were used to analize the quantitative data. Accordingly, the findings of the study indicated that the overwhelming majority (82.2%) of the respondents witnessed the presence of interaction with the adjacent agro-ecological communities. It was identified that highlanders and lowlanders of the zone are interlinked ecologically, economically, socio-culturally and politically. However, due to diminishing of ecological resources, inadequacy of agricultural products and gradual development of resentments between various socio-cultural groups, the status of the linkage is not to the level expected in the study area. In some instances, it steered them to conflict driven by various factors of natural resources, socio-economic and political elements which in turn resulted in humanitarian, social, economic and environmental consequences. Notwithstanding its devastating impacts, both the highland and lowland communities employed the legal and indigenous conflict resolution strategies to curb the problem. Hence, as both the highlanders and lowlanders are vulnerable to some sorts of stresses, seasonality and shocks, strengthening complementarities between them would have invaluable contribution for building resilient livelihoods of both communities, particularly the highly vulnerable lowlanders. / Geography / Ph. D. (Geography)