Historically the resolution of claims under investment treaties has been confidential and private.Over the past fifteen years, however, there have been changes that require greater transparency in the arbitration of disputes under investment treaties.The development with the potential to effect the greatest change in this regard is the recent work of UNCITRAL, through its new Rules on Transparency in Treaty-based Investor-State Arbitration and the treaty designed to give those rules wide application to existing investment treaties (the ‘Mauritius Convention’). This chapter outlines the drivers of change regarding transparency in investor-state arbitration and looks critically at the role of Asian States in this process.While Asian States have been active in the development of treaty policy in a variety of substantive and procedural areas, they have been ambivalent with respect to developments on transparency.In the UNCITRAL negotiations, Asian States expressed considerable doubts about both the need for the Rules on Transparency and the Mauritius Convention.This chapter considers the arguments raised in that context, as well as current Asian State practice, and suggests that the unwillingness of States in Asia to undertake transparency obligations may severely curtail the promise of UNCITRAL’s work.