Model Law on International Commercial Arbitration has been a source of inspiration for numerous countries. In choosing a legal structure، there is a strong tendency towards adopting a monist legal regime based on the Model Law. In Iran، as a result of the ratification of Iranian International Commercial Arbitration Act (ICAA) in 1997، Iranian arbitration law has changed its structure from monism to dualism، that is، the Civil Procedure Code is applicable to domestic arbitration، whereas ICAA applies to international arbitration. The duality of the system is not an appropriate legal structure. This article argues that Iranian arbitration law should be based on monism. It concludes that not only should Iranian arbitration law be in consistent with the Model Law 2006، but it should also extend beyond the Model Law by providing a more comprehensive legislation.