This paper asks whether the rush to regionalism in international trade and investment benefits developing countries. It argues that preferential trade agreements (PTAs) are harmful to the multilateral trade regime in a number of possible ways. As well, their contributions to economic improvement are uncertain at best, and depend on the presence of a number of other factors. In some ways, PTAs may actually harm signatories (loss of tariff revenue, loss of policy space). However, they do provide a platform for negotiated progress on a number of important non-economic objectives, from cementing peaceful political relations to pursuing common environmental problems.