This article provides an overview of the MiFID rules governing the operation of the financial markets. After outlining the policy aims of MiFID, we address in greater detail the new rules that apply to the regulated markets and other systems for the execution of transactions in financial instruments. Next, we analyse the rules regarding market transparency, which help to ensure that market participants can carry out their transactions in financial instruments on an informed basis. We also investigate the interaction between the best execution obligation incumbent upon intermediaries and the competition between market platforms intended by MiFID. The European regulations are likewise explained, together with the specifically national dimensions. Where relevant, mention is also made of recent market initiatives that take advantage of the new MiFID framework.