Rapid demographic growth will add 600 million people to cities and towns in developing countries during the 1990s, about two-thirds of the expected total population increase. Of the world's 21 megacities, which will expand to have more than 10 million people, 17 will be in developing countries. With urban economic activities making up an increasing share of GDP in all countries, the productivity of the urban economy will heavily influence economic growth. This paper analyzes the fiscal, financial, and real sector linkages between urban economic activities andmacroeconomic performance. It builds on this analysis to propose a policy framework and strategy that willredefine the urban challenge in developing countries. ISBN10: 0-8213-1816-0 ISBN13: 978-0-8213-1816-4