This article discusses the possibility of the International Criminal Court's taking domestic investigations and prosecutions of crimes within its jurisdiction where states are unwilling genuinely to investigate or prosecute such crimes. In particular sustaining the admissibility of a case on the basis of the lack of impartiality or independence of national proceedings is subject to analysis. Whereas the lack of this due process guarantee is expressly considered in the Rome Statute as a ground for admissibility where it is meant to shield a person from criminal responsibility, it is not equally clear that a case can be declared admissible where domestic proceedings are or were unfairly conducted to the prejudice of the person concerned. On an analysis of the wording of the Statute, its object and purpose, and its ‘preparatory works’, the possibility of the Court's taking on domestic proceedings on the basis of their being intentionally unfair to the prejudice of a suspect or accused does not appear to have a strong legal basis. However, recent developments at the ICTY and the ICTR show the importance of such a possibility to the fulfilment of the mission entrusted to the ad hoc tribunals. This circumstance brings about crucial questions about the role of the International Criminal Court in the enforcement of international justice and its contribution to international peace and security.