New Zealand is party to several free trade agreements (FTAs), such as those with China, Malaysia, and Korea, that include investment chapters aimed at protecting foreign investors. These chapters also contemplate investor/State arbitration to settle disputes. It is, then, important to keep an eye on recent decisions regarding other FTAs, in order to identify how similar potential disputes involving the government or New Zealand investors abroad are likely be framed. A recent award by an international tribunal in Eli Lilly and Company v Government of Canada applying the North America Free Trade Agreement (NAFTA) is one that deserves close evaluation. (International Centre for Settlement of Investment Disputes, Eli Lilly and Company v Government of Canada. Case No. UNCT/142. 16 March 2017. [Lilly v Canada]). Although the award has a strong intellectual property component, this article deals with a different dimension: how far can a foreign investor dissatisfied with a final court’s new interpretation of national law go in challenging this interpretation before an investor/State tribunal? Not that far. This is the general answer to this question offered by the Lilly tribunal. … but