The purpose of this thesis is to provide a comprehensive framework of a concept that is not novel but uncertain in its application, thus the author seeks to comprehend the elusive concept of moral damage for corporate investor in international investment arbitration. In the first instance, the question of the recognition of the implementation of moral damage in international law would be reconciled with. Which leads to the second formulated problem which is to determine the standard and circumstances that would entail awarding moral damage to corporations in investment arbitration. In solving these issue, the author relies on numerous attempts in international jurisprudences to deduce the accepted mode of remedy for moral damage as well fulfilling the requirement that is consistent with international law. Referring to the notable case before the ICSID tribunal, Desert Line Projects LLC v. Yemen, was the first case that awarded a corporation moral damages. However, as time progressed the notion of awarding moral damage within the meaning of Desert Line, is inconsistent with international law, as it conflates the issue of non-pecuniary injury and punitive injury. Recent arbitral decision, Lemire v. Ukraine, is a case that shed some new light on the issue of moral damages. The tribunal’s implementation of moral damages deriving from public international law to be adopted in investment arbitration entail a high threshold. As such, reconciling the differences, in principle, under public international law and investment law, the event in which moral damage should be awarded to corporations is when a breach of a treaty resulted in loss of reputation, which can be justified as material damage and non-pecuniary injury, thus this notion is consistent with international law.