Derivatives, ranging from relatively simple forward contracts to complicated options products, are an increasingly important feature of financial markets worldwide. They are already being used in many emerging markets, and as the financial sector becomes deeper and more stable, their use is certain to grow. This Handbook provides a basic guide to the different types of derivatives traded, including the pricing and valuation of the products, and accounting and statistical treatment. Also, it aims to highlight the main areas in which derivatives matter to central banks, notably those of monetary policy and banking supervision. It is nt intended as a manual for traders, nor to describe in depth the current state of world markets, where changes can happen so rapidly that any description must soon become outdated. But we do hope to provide a clear enough description of derivatives and their relevance to central banks for central bankers to be confident in tackling the issues that arise. Most derivatives traded are, in fact, fairly simple, and well within the grasp of our intended readership. This handbook is also available in Spanish.