Illegal fishing for toothfish (Dissostichus spp.) in the maritime zones around sub-Antarctic islands in the Southern Ocean has been a considerable problem for many years. Enforcement of fisheries regulation is problematic as the remoteness of these islands has enormous logistic and financial implications. Multilateral hot pursuit, meaning hot pursuit involving pursuing vessels, aircraft or officials with different nationalities, can contribute to making enforcement, and thereby regulation, more effective. The article discusses the hot pursuits of the South Tomi and the Viarsa 1 in the context of applicable international law and state practice. Some of the conclusions are that these types of hot pursuits are not inconsistent with Article 111 of the LOS Convention, that they do not erode the freedom of the high seas or affect the LOS Convention's jurisdictional balance and that they are fully consistent with the objectives of the IPOA on IUU Fishing.