One of the two main themes of the Rio+20 United Nations Conference on Sustainable Development was the reform of the UN institutions for sustainable development (IFSD). Part of the reform package under discussion involves the reorganization of the UN Commission on Sustainable Development (CSD). Following the outcome of the 2002 Johannesburg Summit on Sustainable Development, the CSD Secretariat registered 349 partnerships for sustainable development. In these partnerships, public actors (from governments or international organisations) and private actors (from business or civil society) work together to help implement intergovernmental commitments. A decade after these partnerships were launched in Johannesburg, 2012 would be the ideal year to systematically evaluate their contributions and initiate reforms. The research paper does not aim to make sweeping statements either for or against partnerships. Rather, the idea is to provide an impartial evaluation of the instrument's opportunities and limits. To do so, the study takes transnational water partnerships as an empirical basis for investigating partnerships' performance record and success factors. Building on this analysis, the research paper makes recommendations on how to improve the UN institutional framework for partnerships. To date, the criteria and guidelines for partnerships are not binding and very general in nature; no review mechanism is in place. In the follow-up to Rio+20, the UN should implement necessary reforms.