In 2009 the United Nations launched a new two-tier system of administration of justice. The system is composed of two standing bodies, the United Nations Dispute Tribunal (UNDT) and the United Nations Appeals Tribunal (UNApT), the latter acting as an appeals mechanism against decisions of the UNDT. The former system foresaw the United Nations Administrative Tribunal (UNAT) as the sole body of administration of justice within the UN, while the International Court of Justice (ICJ) acted as review mechanism on the decisions of the UNAT. However, this review system was abolished in 1995 and, since then, no option was available to unsuccessful (or partially successful) staff members for having a UNAT judgment reviewed. The lack of any option for review led to criticisms and instances for reform of the whole system, which eventually led to the establishment of a Redesign Panel, which suggested the establishment of a two-tier system of administration of justice, with the aim of meeting the 'basic standards of due process established in international human rights instruments'. The recently established Appeals Tribunal should fill the gap created by the abolition of the ICJ competence to review the judgments rendered by the UNAT. This article evaluates the improvement to the system represented by the establishment of the United Nations Appeals Tribunal in three main steps. The first is the identification of the shortcomings of the previous review mechanism before the ICJ. The second is the overview of the problems of the former system of administration of justice within the UN. The third and final step is the analysis of the scope of jurisdiction of the new UNApT.