In April 2007, the Pre-Trial Chamber I of the International Criminal Court (ICC) issued its first arrest warrants with regard to the situation in Darfur. Addressees of these measures are the Minister for Humanitarian Affairs and former Minister for the Interior Ahmad Harun and the alleged Janjaweed leader Ali Kushayb, who both at the time of writing have not yet been surrendered to the ICC. On the contrary: Sudan consistently invokes its national sovereignty and its ability to prosecute its nationals itself. However, with regard to Harun and Kushayb, there is reason to hold strong doubts as to Sudan's ability and willingness to seriously prosecute them. Therefore, this article assesses the admissibility of these two cases before the ICC, focusing on the principle of complementarity. For this the article starts with an overview of those aspects of the principle of complementarity which are relevant for the situation in Darfur. A thorough analysis of the status of the Sudanese judicial system both before and after the adoption of the Interim National Constitution of Sudan in 2005 follows, before, finally, the application of the principle of complementarity to the two cases is assessed against the results found.