This book proposes and outlines a comprehensive framework for judicial protection in transnational criminal proceedings that ensures the right to judicial review without hampering the effective functioning of international cooperation in criminal matters. It examines a broad range of potential approaches in the context of selected national criminal justice systems, and offers a comparative analysis of EU Member States and non-Member States alike. The book particularly focuses on the differences between cooperation within the EU on the one hand and cooperation with third states on the other, and on the consequences of this distinction for the scope of judicial review.