Does foreign aid spent on trade facilitation increase trade flows of developing countries? There is an on-going and high profile discussion of aid-for-trade associated with the Doha negotiations of the World Trade Organization. There continue also questions about how best to achieve the Millennium Development Goals. The analysis in this paper explicitly considers how to target aid most effectively to increase trade a fundamental question related to the crisis and policy debate over restarting the world trading system. Using detailed data on aid flows from the OECD, the analysis here estimates the responsiveness of trade flows to specific types of foreign aid. The findings indicate that aid directed toward promoting trade enhances the trade performance of recipient countries: a 1 percent increase in aid directed toward trade policy and regulatory reform (amounting to about US1.7 million more such aid) could generate an increase in global trade of about US18 million. This yields a "rate of return" on every dollar of this type of aid of about US97 in additional trade. As the dollar aid flow is relatively small, such targeted aid mitigates concerns about absorptive capacity and real exchange rate appreciation, which may accompany larger disbursements.