Regardless of obscure terminology and judicial practice, what is clear is that the doctrine of inherent powers mainly aims at remedying possible gaps in the legal regulation of proceedings, with a view to serving one or more of the following purposes: (a) to ensure the fair administration of justice; (b) to control the process and the proper conduct of proceedings; and (c) to safeguard and ensure the discharge by the court or tribunal in question of its judicial functions.3

In this paper, I focus on the assertion of inherent powers in the context of arbitration under the auspices of the Convention on the Settlement of Investment Disputes between States and Nationals of Other States (ICSID Convention),4 in hopes of providing a first systematic overview of the relevant practice. The analysis that follows demonstrates that, unsurprisingly, ICSID arbitral tribunals perceive their judicial function much like other international courts and tribunals.5 Nonetheless it is always interesting to note that the doctrine serves as a further unifying factor despite the ad hoc basis and operation of ICSID tribunals. Section B seeks the legal source of the assertion of inherent powers, emphasizes their functional justification, and analyzes the relevant practice of other international courts and tribunals. Section C will examine certain illustrations of the concept in the practice of ICSID tribunals. Section D addresses limitations to the exercise of such powers safeguarding against arbitrators’ overreach. Section E concludes.