I survey some recent research on the role of patents in encouraging innovation and growth in developing economies, beginning with a brief history of international patent systems and facts about the current use of patents around the world. I discuss research on the implications of patents for international technology transfer and domestic innovation. This is followed by a review of recent work by myself and co-authors on regional patent systems, the impact of patents on firm performance, and the impact on pharmaceutical patenting and domestic innovation. The conclusion suggests that patents may be relatively unimportant in development, even for middle income countries. Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.