This article examines the limitations of the choice of law caused by Internationally Mandatory Rules in Entering into the Turn-Key Contracts. In June 2007, Clough Engineering, a corporation based in Western Australia, approached the Federal Court of Australia seeking injunctive relief and leave to commence proceedings against an entity located outside Australia, the Oil & Natural Gas Corp of India (ONGC). Clough had contracted with ONGC to provide a range of services in relation to the construction of gas and oil wells off the coast of India. The contract was governed by Indian law, and included a clause by which the parties agreed to submit their disputes to arbitration. Yet the Federal Court assumed jurisdiction over the dispute, principally because Clough had framed its claim as a plea for relief for contraventions of Australia's Trade Practices Act 1974. The result of this cases that it is possible for an arbitral tribunal to hear a claim made under the Trade Practices Act even if that claim arises “in connection with”a contract the proper law of which is not the law of Australia.However, in Transfield Philippines Inc v Pacific Hydro Ltd, the turnkey contract included a choice of law provision, selecting the law of the Philippines, and a clause providing that all disputes arising out of or in connection with the agreement were to be arbitrated under the ICC Rules, with the seat in Singapore. Hearings were in fact conducted in Melbourne, Australia, although all awards were published in Singapore. The result of this cases that it would not be appropriate for an Australian court to adjudicate claims for misrepresentation under Australian statutes dealing with misleading and deceptive conduct, once the arbitral tribunal had determined, applying appropriate choice of law rules, that such claims are governed by the law of the Philippines. To do so would lead to a multiplicity of proceedings, usurp the jurisdiction of the tribunal and deny the intention of the parties as expressed by them in the arbitration agreement.In short, the Internationally Mandatory Rules as an active part of public order create limitation of party autonomy in choice of law rules in a different way. The court is fully entitled to refuse to use those rules of law applicable on the contract which are in the contradiction to the internationally mandatory rules of law of the forum. And the court may give an effect to those Internationally Mandatory Rules that form a part of a law of foreign country when deciding about applicability of certain rules of applicable law.