The Generalized System of Preferences (GSP) provides duty-free tariff treatment to certain products imported from designated developing countries. The United States, the European Union, and other developed countries implemented such programs in the in the 1970s to promote economic growth in developing countries by stimulating their exports. The U.S. program (as established by Title V of the Trade Act of 1974) was last reauthorized through December 31, 2006 in section 4101 of the Trade Act of 2002 (P.L. 107-210). Congress may consider legislation (H.R. 6142) under suspension of the rules to, among other things, renew the preference for two years. H.R. 5070 seeks to renew the preference for one year and H.R. 6076 and its companion bill S. 3904 would renew GSP for two years. S. 191 seeks to extend AGOA-type benefits to certain Asian and Pacific least-developed countries, including an extension of GSP for these countries alone. In previous years that the GSP was set to expire, its subsequent renewal was generally considered noncontroversial. Even when the preference was allowed to lapse, as it has at several times in its history, it was widely expected that Congress would retroactively renew the preference. However, this year, due to the present impasse in multilateral trade talks in the World Trade Organization Doha Development Agenda (DDA) and congressional concerns regarding the inclusion of certain more advanced developing countries such as India and Brazil in the program, renewal of the preference seems more tenuous. This report presents a brief history, economic rationale, and legal background leading to the establishment of the GSP; a brief comparison of GSP programs worldwide, especially as they compare to the U.S. program; the U.S. implementation of the GSP and the present debate surrounding its renewal; an analysis of the U.S. program's effectiveness and the positions of various stakeholders; and possible implications of the expiration of the U.S. program.