Ex aequo et bono is a means of resolving disputes in light of fairness and good conscience. The principle has been known to jurists since the classical period of Roman Law, but commentators and practitioners have avoided using it for fear of its potential unpredictability. Being controlled by the perception that ex aequo et bono brings irreconcilable uncertainties and undue exercise of authority by arbitrators, arbitration lawyers have not extensively investigated whether their negative understanding of ex aequo et bono can still be maintained in the current arbitration environment under the United Nations Commission on International Trade Law (UNCITRAL) Model Law regime. The main objective of this article is to suggest that arbitration lawyers’ negative understanding of ex aequo et bono is not supported by adequate legal research. This article analyses the literature on ex aequo et bono and identifies the gaps in the research.