For the LDCs reducing trade is doubly important because since they start from a lower base, they can potentially derive disproportionately higher benefits compared to other countries. Thus LDCs are taking necessary measures aimed at lowering trade costs either on their own or with the support of the private sector, and some have achieved considerable success. However, they are unable to make a transformative shift because of limited institutional capacity and resource constraints. This is where aid for trade can help, as evidenced by the success achieved by various multilateral, regional and bilateral aid-fortrade initiatives. The paper shows that the impact of aid-for-trade intervention on reducing trade costs in LDCs tends to be higher when they include a robust and credible analytical work, a high level of country ownership, institutional capacity building on a sustained basis, continuous support for a sufficiently long period, resource leveraging and a co-ordinated response from donors. Moreover, such intervention can be successful if political economy challenges are appreciated, mainstreamed and mitigated.