The determination of the nationality of legal entities is one of the most significant issues in international investment law, as access to the protections afforded by investment treaties and international investment arbitration mechanisms largely depends on the investor’s nationality. Although this practice is generally regarded as a legitimate aspect of investment planning, in certain circumstances it may be employed as a tool for artificially creating arbitral jurisdiction and opportunistically exploiting the investment dispute settlement system. Using a descriptive-analytical method and relying on library-based sources, The findings indicate that investment arbitral practice does not prohibit nationality structuring per se; rather, it considers such conduct abusive when the restructuring of nationality occurs after a dispute has become reasonably foreseeable and is undertaken primarily to establish arbitral jurisdiction. Furthermore, factors such as the timing of nationality restructuring, the foreseeability of the dispute, the existence of substantial business activities, and compliance with the principle of good faith constitute the most important indicators for identifying abuses of nationality structuring. The study concludes that the legitimacy of nationality structuring should be assessed through a combination of formal and substantive criteria, and that reliance solely on traditional nationality tests is insufficient to prevent abuse within the investment arbitration system. Accordingly, a combined model based on the simultaneous assessment of temporal, economic, and behavioral factors is proposed as a more effective framework for distinguishing legitimate nationality structuring from abuse of process.