How to fight irregularities affecting the financial interests of the European Union? Are legal regulations effective? What needs to be changed? Fight against EU fraud - administrative and criminal law issues addresses these important questions. It explores the most recent development tendencies in the protection of the EU budget, with regard to both the administrative and criminal law, especially in light of the changes of the criminal law framework for the protection of the European Union's financial interests resulting from the Treaty of Lisbon and the proposed modifications of the legal framework of OLAF's activities. Also, it presents the criminal legal framework with particular emphasis on the fight against offences detrimental to the EU budget, as well as on the practical experience of co-operation in this area. Moreover, the book covers the problems of conducting audit which plays a crucial role in the prevention and detection of irregularities. The experience of the European Court of Auditors and the Supreme Audit Office and their role in the protection of the EU financial interests are analyzed. Some more theoretical issues are also examined such as the idea of the European Union as a laboratory of internationalization of criminal law. The authors are some of the most renowned experts in the field, including Dr Simone White, Prof. Eleonora Zielinska and Prof. Lech K. Paprzycki. The scientific editor is Dr Celina Nowak, assisting professor at Kozminski University.