The relative importance of developing countries has grown as they expanded their fishing efforts and as a result of over-fishing in OECD countries. Aquaculture production has expanded significantly. And many of the stocks of fish species in international trade are either fully or over-exploited while a number of other stocks are depleted or recovering. Previous rounds of multilateral trade negotiations have produced positive outcomes for the trade in fish products. However, there remain a number of market measures that can hinder trade. Is there scope for further liberalisation in the world fisheries sector? What are the key trade and market measures on which policy attention should be focused? What will further trade liberalisation mean for the sustainability of fish resources? This publication reviews the significant changes that have taken place in the world fisheries sector and provides an in-depth analysis of the prospects for and potential effects of further market liberalisation in the sector. It also contains an inventory of market measures and policies in place in OECD countries. A principal outcome of the study is that there is room for further market liberalisation in the trade in fish and fish products.