Geographical and substantive regulatory gaps in high seas fisheries are serious weaknesses in the current global regime for the governance of marine capture fisheries. This article discusses recent developments on the establishment of new regional fisheries management organizations (RFMOs) and arrangements, identifies geographical gaps and examines scenarios to fill these. In view of the need for upgrading existing fishery bodies to ensure compatibility with the UN Fish Stocks Agreement, ample attention is devoted to the tool of performance assessments. Also examined in depth are the constraints for coastal States that wish to exercise their sovereign rights in relation to fishing practices that impact on sedentary species on their outer continental shelf. The discussion of the reform of the international legal regime for high seas fisheries is in particular devoted to discrete high seas fish stocks.