A major success of the early post-war period was the negotiated reduction of barriers to international trade in commodities and manufactured goods, under the auspices of the GATT. The current challenge is to achieve a similar liberalization for trade in services - the sector which has overtaken manufacturing as the largest provider of jobs and growth in the advanced economies. The difficulties are legion. Data are scarce and definitions are contentious. There is no clear equivalent in services of the zero-tariff objective that can be defined in the trade of goods. Domestic service markets are often imperfect and each country has its own regulatory structure to protect consumers. Many developing countries are sceptical about the effects of freer service trade on their economies. This paper develops an analytical framework to clarify negotiating objectives. It assesses the European Community's approach to liberalization and warns of the dangers of seeking 'equivalent reciprocity'. It suggests that a different approach and set of objectives are appropriate to the GATT, which lacks well-defined procedures for policy review and settlement of disputes, and whose members are more diverse. Finally, it evaluates the prospects for multilateral service liberalization in the Uruguay Round and in the EC by 1992, and suggests that such efforts can be complemented by unilateral and bilateral liberalization in certain service sectors.