In May 2010 Australia commenced litigation against Japan in the International Court of Justice over the legality of Japanese scientific whaling in the Southern Ocean. This article considers the background to the litigation, the basis of Australia’s opposition to whaling, and the grounds upon which Australia is mounting its challenge. The interpretation of the 1946 International Convention for the Regulation of Whaling and the operation of the International Whaling Commission are considered in light of the precautionary principle. The article concludes that Australia’s success depends upon a broad reading of the Convention that takes into account its objects and purposes, as well as wider developments in international law. Any guidance that the International Court of Justice can provide on the modern interpretation of this now dated Convention is to be welcomed.