Abstract The dispute over the Matthew and Hunter Islands (MHIs) has long been a constant strain on Vanuatu-French relations. The article examines this dispute in light of the Chagos Advisory Opinion and a few other cases concerning territorial disputes. It first submits that sovereignty over the MHIs had never been raised until 1962, when, at the occasion of a private claim, France and Britain, the two administering powers of the New Hebrides at that time, considered the issue. The two states reached an agreement in 1965, asserting that the MHIs were part of the French colony of New Caledonia and not the British-French Condominium of the New Hebrides. This article then considers the legal implications and lawfulness of the agreement, which did not take into account the local populations’ will. Although there are some important differences between the Chagos and MHIs disputes, mainly due to the fact that the MHIs are uninhabited, the applicability of the right of self-determination to both cases is nevertheless beyond doubt. The article contends therefore that the 1965 Agreement between France and Britain may constitute a violation of the right to self-determination of the people of the New Hebrides (Vanuatu), who were not consulted on the decision to attach the MHIs to the French territory of New Caledonia, and suggests that there may be, however, some other legal principles under international law that can come into play. Finally, the article contends that negotiated solutions could be a potential way forward for the parties involved.