In recent years, private capital inflows to some developing countries have increased sharply. This increase has provided the financing needed to enhance the use of existing capacity and to raise investment levels. But capital inflows produce their own problems. They can increase inflation and lead to exchange rate appreciation, for example. The authors review the macroeconomic repercussions of an increase in capital inflows. Generally, it will result in appreciation of the real exchange rate, a larger nontradable sector, a smaller tradable sector, and a larger trade deficit. Under a fixed exchange rate regime, it will also result in faster inflation and an accumulation of foreign reserves. Can government intervention minimize the size and effects of real exchange rate appreciation? The authors discuss different mechanisms that can be used to limit the appreciation - and discuss the difference, in this respect, between portfolio investment and external debt. Finally, they review and compare the recent experiences of four Latin American countries (Argentina, Chile, Colombia, and Mexico) and five East Asian countries (Indonesia, Malaysia, the Philippines, the Republic of Korea, and Thailand), and discuss how these countries have dealt with the macroeconomic side effects of capital inflows. The authors found the following: All nine countries have avoided a permanent, significant increase in inflation, it can be argued. In Argentina and Mexico inflation has been decreasing for three or four years, and in the other seven countries it has remained stable. The countries that received the largest average capital inflows (as a proportion of GDP) in 1989-92 are not those that experienced the greatest exchange rate appreciation. In fact, the countries with the greatest capital inflows (Chile, Malaysia, and Thailand) have experienced either depreciation or low appreciation of their currencies. (Appreciation was lower in Thailand than in Korea despite much greater capital inflows in Thailand.) Countries with decreasing government consumption as a percentage of GDP (Chile, Indonesia, and Malaysia) showed less appreciation of the real exchange rate. Countries with increasing government consumption as a percentage of GDP (Argentina, Korea, Mexico, and the Philippines) showed the greatest appreciation of the real exchange rate, despite not receiving the greatest capital inflows.