In 2008, Ecuador raised the need for the creation of an alternative dispute resolution mechanism within the Union of South American Nations (UNASUR). Any system of investment arbitration should comply with democratic principles and the international rule of law which provide predictability, transparency and legitimacy for arbitral decisions and thus should avoid political and economic bias. This article shows Latin America’s historical inclination towards arbitration and focuses on the 2014 UNASUR Project’s proposed method of appointment and disqualification of arbitrators, and its approach to the execution of awards. By way of comparison with International Centre for Settlement of Investment Disputes (ICSID) tribunals, the article goes on to suggest how an application of the international rule of law could help guide and structure arbitrators’ behaviours in the proposed UNASUR Project as well as under the current ICSID framework to avoid arbitrators’ deviation from the law and prevent their creative, independent interpretations.