Dr. Diokno is a former Secretary of Budget and Management. He is currently Chairman of the Board of Trustees of the Pamantasan ng Lungsod ng Maynila and concurrently Chairman of the Board of the Ospital ng Maynila. He is an Independent Director of Asia United Bank, and a Senior Adviser of the International Tax and Investment Center (ITIC).

Professor Diokno teaches Economics at the University the Philippines School of Economics. He provides policy advice and conducts research in public economics, resource economics, and development economics (with focus on ASEAN transitional economies).

He served the Philippine Government as Secretary of Budget and Management (1998-2001), Fiscal Adviser to the Philippine Senate, Chairman and CEO of the Philippine National Oil Company (PNOC), and Chairman of the Local Water Utilities Administration.

He has officially represented the Philippines in various international forums.

He has served as adviser/resource person for the World Bank, the Asian Development Bank, the International Monetary Fund, the U.S. Agency for International Development, the Canadian International Development Administration, and the European Commission.

He is a political and economic commentator. He writes an op-ed for the Business World, the Daily Tribune and the Malaya Business Insight.