Internationalised courts are now fi rmly part of the international criminal landscape, having been established when post-confl ict national systems were unable to try the perpetrators of mass atrocities, or when international contribution was deemed warranted. Internationalised courts have been established in Kosovo, East Timor, Sierra Leone, Cambodia and Bosnia and Herzegovina. One of the shared characteristics of these courts is that they necessarily interact with the national courts in their countries of operation; some more successfully than others. In some cases, national courts have signifi cantly hindered the work of the internationalised court. Given that the expense of the ad hoc tribunals and the complementarity regime of the ICC mean that internationalised courts are likely to be the forum of choice in many post-confl ict states, an examination of how these courts can best manage relationships with national courts is timely.