The ICJ’s treatment of US practice translates into one of the most controversial aspects of the Jurisdictional Immunities judgment. The Court’s approach was elusive and patchy. Certain key decisions by US courts in the field of sovereign immunity were patently neglected, while others were addressed in a misleading manner. This article examines the Court’s citations and omissions relating to US practice, with respect to both the jus cogens and tort exception arguments advanced by Italy in defense of its Ferrini jurisprudence denying immunity when the defendant State is accused of egregious breaches of human rights. The article also enquires into the possible reasons at the root of the Court’s inadequate assessment of US practice. It takes the view that the Court’s dismissive attitude vis-à-vis the anomalous American experience casts doubt over the judgment’s reliability and persuasiveness as an accurate reflection of the contemporary law of State immunity.