This paper describes a methodological approach for a sustainability assessment of development cooperation projects. Between the scientific disciplines there is no agreement on the term of "sustainability". Whereas the definition of sustainability within the context of development cooperation frequently highlights the long-term success of an intervention, the United Nations herald the inclusion of social, economic and environmental aspects. This paper proposes to bridge this gap by providing an analytical framework that uses nine impact category groups based on thematic priorities of sustainable development derived from the Sustainable Development Goals. Additionally, the long-term effectiveness of a project is taken into consideration. These impact category groups comprise the analytical framework, which is investigated by the Life Cycle Assessment and an indicator-based analysis. These data are obtained through empirical social research and the LCA inventory. The underlying concept is based on life cycle thinking. Taking up a multi-cycle model this study establishes two life cycles: first, the project management life cycle; and, second, the life cycle of a project's innovation. The innovation's life cycle is identified to have the greatest impact on the target region and the local people and is consequently of primary interest. This methodological approach enables an ex-post sustainability assessment of a built innovation of a development cooperation project and is tested on a case study on Improved Cooking Stoves in Bangladesh. © 2016 by the authors.