The article analyses whether international criminal procedure is "adversarial", "inquisitorial" or mixed. It examines the law of the ICTY and the ICC, including the relevant case law. This law has developed from an adversarial to a truly mixed procedure by way of various amendments of the ICTY's Rules of Procedure and Evidence (RPE) and the drafting of the Rome Statute merging civil and common law elements in one international procedure. It is no longer important whether a rule is either "adversarial" or "inquisitorial" but whether it assists the Tribunals in accomplishing their tasks and whether it complies with fundamental fair trial standards. As to an efficient trial management an UN Expert Group called for a more active role of the judges, in particular with regard to the direction of the trial and the collection of evidence. In this context, it is submitted that a civil law like judge-led procedure may better avoid delays produced by the free interplay of the parties. Ultimately, however, the smooth functioning of a judicial system depends on its actors, procedural rules provide only a general framework in this regard. A truly mixed procedure requires Prosecutors, Defence Counsel and Judges who have knowledge of both common and civil law and are able to look beyond their own legal systems.