Recent years have witnessed a sharp increase in the number of regional trade agreements (RTAs) both concluded and under negotiation. This paper attempts to document and discuss this growth, focusing on the United States (US), the European Union (EU), China, India and the agreements of other countries. The form, coverage and content of these agreements vary considerably from case to case. This paper poses the following questions: why so many, why the variation, and why the recent increase in RTAs? Implications for the trading system are discussed in the final section.