In the final year of his presidency, President George W. Bush issued an Executive Order which reorganized and renamed the President's Foreign Intelligence Advisory Board (PFIAB) to President's Intelligence Advisory Board (PIAB). The precursor to PFIAB and PIAB, the President's Board of Consultants on Foreign Intelligence Activities was established by President Dwight Eisenhower in 1956. It aimed to provide the president a nonpartisan evaluation of the role and effectiveness of the U.S. intelligence collection, covert actions operation, counterintelligence, and intelligence analysis. The board has addressed three broad areas over the years. First, it assessed the impact of new technologies and innovative modes of organization to the collection and analysis of intelligence. Second, it analyzed foreign political trends. Third, it provided assessment of crisis management. Despite of the significant activities performed by the board, it remains to be the smallest and the least well-known part of the U.S. intelligence community. This article focuses on the President's Foreign Intelligence Advisory Board (PFIAB). It determines why it remains to be the least known part of the intelligence community and how it functions and operates. The article also discusses the evolution of the board from the perspective of the administration of Eisenhower, Kennedy, Johnson, Nixon, Ford, Carter, Reagan, George H. W. Bush, Clinton, and G. W. Bush. While the PFIAB has been doubted of its relevance, it has remained to play a useful role for both the president and the overall intelligence community. Uniquely positioned, it has a clearance to review all of the most sensitive secrets and it has direct access to the president. It is a powerful and effective tool that supports the president's efforts to implement policies, manage operations of the intelligence community, and change organizations. Although much debate has been directed on the potential and the role of the institution, it has nevertheless made important recommendations such as the establishment of DIA, CIA's Directorate of Science and Technology, and Defense Attaché system; all of which improved the intelligence system.