The paper answers the question of whether investor-state dispute settlement (ISDS) discriminates against nationals. This issue was actually settled in 1926 in Hopkins v Mexico. The complaint that ISDS is discriminatory as a matter of principle has surfacedbefore the German constitutional court in the context of the ratification of the Comprehensive Economic and Trade Agreement between Canada and the European Union (CETA). It is predicated on the fact that only foreigners have legal standing, whereas nationals cannot take legal action against measures of their own government before an investment tribunal. As a corollary, foreign investors have an extra venue at their disposal to challenge statemeasures. The case is argued, in part, on the basis of the principle of equality before the law. It is undisputed that equality before the law includes procedural law. It entails that like cases are treated equally in terms of appellate review. The Federal Constitutional Court was able to leave the question of discrimination open in the applications for a preliminary injunction. It will have to take a stand, however, in the principal proceedings and examine the issue in light of the German constitution, for what is being impugned is the ratification act which is subject to national law. If the Court were to side with the applicants, it would deal a death blow not only to CETA in its present form, but to the multilateral investment court system promoted by the European Union and, in particular, Germany. The point made by the applicants in the CETA complaint is not only of importance to a German constitutional law context. If ISDS is per se discriminatory is a fundamental issue which requires answering before any reform steps in relation to ISDS are being addressed.