This article analyses interlinks between environmental changes, conflicts and sustainable development in the Horn of Africa. It makes an argument for the dialectical correlation between the three variables. It is thus argued that environmental deterioration can lead to conflicts, and environmental deterioration and conflicts can also hamper sustainable development. It is also argued that lack of sustainable development can lead to environmental degradation, which can lead to conflicts. Conflict causes environmental degradation, which hampers development. The article also argues that social structures and socio-economic mode of life impact on environment that either aggravates or mitigates conflicts, affecting sustainable development negatively or positively. The social norms, values and practices these social structures and institutions spawn also impact on environment-conflict-development nexus.