The following article presents the European Court of Auditors’ (ECA) approach to auditing public procurement for activities co-financed from Structural Funds. It discusses the regulatory framework for public procurement as set out in the EU Directives and national laws and the Structural Funds Regulations. It then explains the main features of its audit methodology underlying the annual Statement of Assurance and how this applies to public procurement audits. According to the Court’s audits, problems of non-compliance with EU and national public procurement rules are often related to a weak implementation of existing rules (rather than overly complex legal provisions). This is an important aspect to be kept in mind in view of an effective simplification of the current legal framework.