Validity of Res Judicata of Arbitration Awards in the Iranian and American Law

The purpose of res judicata in arbitration awards is that if the presented dispute has been already considered between the same parties or their representatives and a final judgment has been issued in that respect, the said judgment is precluded the re-litigation of that dispute. Considering that, in the Iranian law, there is no stipulation on the res judicata effect in arbitration proceedings, the findings of this article demonstrate that there is no difference in the necessity of applying this rule between the court judgment and arbitration award in this respect. Non-admission and rehearing of the dispute object in arbitration tribunal is the result of the parties̕ first agreement and concluded contract to refer to arbitration. In the United States law the res judicata effect of arbitration award in judicial decisions has been accepted on the basis of issue preclusion and claim preclusion.