The international normative framework governing the protection of foreign investments in general and the design as well as practice of investor-state dispute settlement proceedings in particular have more recently emerged as central normative »battlegrounds« for competing narratives of global constitutionalization. Against this background and in an attempt to assess this phenomenon, the contribution starts by drawing attention to the concept of narrative and how it might lead to a fruitful narrative turn in international legal scholarship. In addition, it discusses the benefits of applying a narrative perspective to the multi-faceted issue of constitutionalization in the international legal order as a whole. In this regard, it is demonstrated that an empirical approach based on a narrative perspective can be regarded as an objective method to distinguish between possible constitutional law and norms of a non-constitutional character in the international legal order; thus offering a suitable solution to address the fundamental rule of recognition problem of global constitutionalism. Based on these findings, the subsequent sections illustrate how the narrative approach contributes to assessing processes of (de-)constitutionalization in international investment law, thereby, however, also indicating the conceptual challenges arising in connection with empirical research in this particular legal realm.