This paper re-examines the relationship between international capital flows and economic growth within the context of various ‘conditional factors’ that possibly have the potential to influence such relationships. It achieves this by employing panel data for 80 countries that cover 1976–2007. International capital inflow is broken down into foreign direct investments (FDI) and foreign portfolio investments (FPI). We find interesting evidence that only FDI has a positive effect on growth and that FPI has an unfavorable, if not negative, effect on growth. The conditional variables of banking liberalization, high-income level, twin crises, lower corruption, and human capital mitigate the positive impacts of FDI on growth. In contrast, the middle-income level and good shareholder protection have a positive effect. As concerns FPI, the level of financial liberalization, being in a Latin American region, the wealth of countries, and market governance all influence the way that FPI affects growth, whereas the conditional variables of twin crises and human capital do not influence the effect of FPI on economic growth.