The article looks at whether domestic courts should give arbitral awards issue preclusive effect. While issue preclusion may be a concept peculiar to common law systems, the author argues that the international legal order underpinning international arbitration as well as various party-based and systemic benefits of issue preclusion argue for its application to arbitral awards. The paper then discusses three approaches to determining whether an award should have issue preclusive effect, ie the conflict of law approach, the comparative law approach and the transnational law approach, and their respective advantages and disadvantages. Arguing that the transnational approach best serves and captures the characteristics and rationale for international arbitration, the paper outlines conditions under which a court may give an award issue preclusive effect using the New York Convention, current country practice and the ILA recommendations on res judicata as criteria sources.