This report presents the results of an assessment of the United Nations Environment Programme (UNEP) conducted by the Multilateral Organisation Performance Assessment Network (MOPAN). MOPAN assesses the organisational effectiveness of multilateral organisations based on a survey of stakeholders and a review of documents. MOPAN does not assess an organisation’s development results. The role of the United Nations Environment Programme is to be the leading global environmental authority that sets the global environmental agenda, that promotes the coherent implementation of the environmental dimension of sustainable development within the United Nations system and that serves as an authoritative advocate for the global environment.1 For over ten years, governments have deliberated on how to improve the effectiveness and efficiency of the international environmental governance system (including UNEP). This is one of the major issues on the agenda of the UN Conference on Sustainable Development that will be held in Rio de Janeiro in June 2012 (Rio+20). Since 2008, UNEP has been implementing a management reform process to improve its effectiveness based on a re-definition of its subprogrammes and the introduction of a matrix management approach. In 2011, MOPAN assessed UNEP based on information collected at the organisation’s headquarters and in eight countries: Bangladesh, Bolivia, Brazil, Burundi, Ecuador, Nepal, Peru, and Tanzania. The survey targeted UNEP’s direct partners, peer organisations, and MOPAN donors based in-country and at headquarters. To account for UNEP’s limited country presence and capture its normative work, direct partners and peer organisations at the regional and global level were also invited to participate. A total of 215 respondents participated in the survey. MOPAN’s document review assessed UNEP through an examination of publicly available corporate documents and country programming documents from the countries selected. MOPAN assessments provide a snapshot of four dimensions of organisational effectiveness (strategic management, operational management, relationship management, and knowledge management). The main findings of the 2011 assessment of UNEP are summarised below.