AbstractDespite all the advantages of international arbitration, it has never been considered as an entirely independent and complete dispute settlement system and as such has been traditionally assisted by national courts. Nevertheless, the optimum model for courts' involvements in international arbitration is not clear. More importantly, given the latest development in the theory and practice of international arbitration, the necessity and nature of such involvement is under question. Accordingly, this thesis aims to determine the optimum scenario of court involvement in international arbitration in order to enhance its efficiency by providing a fairly harmonised (transnational) approach regarding court involvement in the various stages of international arbitration.Taking efficiency consideration as the main guidance and indicator in modern legal scholarship, the thesis will develop normative discourse regarding harmonization of court involvement in international arbitration based on the comparative and analytical study of two major jurisdictions, the United Kingdom and the United States, and will suggest different solutions which can minimize the need for court's involvements through their substitution by other mechanisms such as party autonomy as well as the expansion of the competence and the authorities of arbitral tribunals.To achieve the desired result, this thesis will analyse and respond to the following fundamental questions: (a) Why, where and when can national courts become involved in arbitration cases? (b) Is there any potential conflict between national courts' competence and the historical facts regarding independence of international arbitration? (c) What are the potential solutions to harmonize court involvement in international arbitration at each stage? (d) To what extent can it be argued that national courts should waive part of their authority in favour of international arbitration in order to enhance the efficiency of international arbitration? (e) What are the potential avenues that need to be explored in order to harmonize court involvement in international arbitration?After examining the above mentioned questions, the thesis concludes that courts' involvement in international arbitration may occur in 4 different stages, namely, before the establishment of arbitral tribunal, at the commencement of arbitration process, during the arbitration and finally at the time of recognition and enforcement of foreign arbitral award. It also suggests that prior to establishment of arbitral tribunal, recognition of a concurrent jurisdiction for the court of the place of arbitration can significantly remove the potential obstacles in front of the conclusion of the tribunal. Moreover, and given the extended role of party autonomy in selecting substantive and procedural law, arbitrating parties can minimizes the possibility of recourse to national courts at the commencement of the tribunal and during the process by submitting their claims arbitration institutions which can offer most of the services offered by national courts and as such will remove the need for national courts intervention. Finally, the thesis proposes that although recognition and enforcement of arbitral award may inevitably require the involvement of local courts, development of a transnational notion of public policy and arbtirability based on efficiency will lead to a sort of universal approach in the enforcement of international awards regardless of the place of business or the nationality of the party-debtor in arbitration.