Public sector management reforms in OECD countries have involved a greater emphasis on issues of performance, reflected both in increased self-evaluation by public sector organisations and evaluation by external performance review bodies. At the same time, national audit institutions, both external (such as auditors-general, courts of audit) and internal (such as inspectors-general) have expanded their scope to include questions of performance. What is the appropriate relationship between performance audit and other forms of performance reviews? This publication considers the relationship between performance auditing and public sector modernisation and the extent to which performance auditing could or should improve the performance of public sector organisations. Despite differing audit traditions and institutional arrangements among OECD countries, there are many common issues. Audit is increasingly seen as a major aspect of accountability in government, but not a substitute for it. Audit organisations are perceived as playing a major role in facilitating -- or impeding -- public sector modernisation.