Most of ADB's lending comes from its ordinary capital resources, offered at near-market terms to lower- to middle-income countries. ADB also provides loans and grants from Special Funds, of which the Asian Development Fund is the largest. The Asian Development Fund offers loans at very low interest rates and grants that help reduce poverty in ADB's poorest borrowing countries.

By the end of 2010, ADB was administering 37 trust funds to finance activities in various sectors or for specific themes, including poverty reduction, governance, gender and development, managing for development results, HIV/AIDS, water, energy, education, information and communication technology, and trade and finance.