In the last twenty years, the European Court of Auditors has placed increasing importance on the production of ?special reports? examining the economy, efficiency and effectiveness of EU spending (the three ?E?s). This institutional focus on performance audit, alongside traditional financial and compliance audit, has occurred at a time when the European Union is increasingly evaluating its own policies and programmes, under political pressure to demonstrate their added value. With performance audit, the EU's external auditors make value judgements on what was achieved through the EU budget, arguably bringing a greater political dimension to the Court as it works to deliver conclusions and recommendations meant to assist the legislature (European Parliament) in carrying out its scrutiny role and the executive (European Commission) in shaping better future policy. This raises questions about how financial accountability is interpreted, and whether it depends on the quality of audit reports or on the forums to which they are delivered, and subsequently, how they act upon them. This article analyses the factors that explain the increased use of special reports by the Court, questioning if they resemble evaluation studies. It examines their focus and impact, as well as the institutional challenges implicit in performance audit.