The paper contains a theoretical discussion of the role of secrecy in the implementation of monetary policy. It documents the Federal Reserve's defense of secrecy as argued in a recent Freedom of Information Act suit. The Federal Reserve's arguments are evaluated on the basis of economic theory. Theoretical papers related to the secrecy issue are reviewed. The discussion highlights a number of potential benefits and costs of central bank secrecy, and identifies some conditions under which secrecy could be socially beneficial.