The issue of whether and how to regulate short selling has vexed regulators for some time. While there are a number of potentially damaging consequences that are said to stem from short selling, there is also evidence that it can have beneficial effects on financial markets. In the wake of the collapse of Lehman Brothers in September 2008, and more particularly the falls in the prices of listed financial securities that followed, the regulation of short selling has come back onto the regulatory agenda with a vengeance. Various regulatory techniques, some temporary and some more permanent, have been adopted to deal with short selling. This paper explores those implemented in the US, the UK, Germany and France. The EU has also been developing its regulatory response and in March 2012 the final text of a Regulation dealing with short selling was published. This paper considers the arguments for and against the regulation of short selling, and considers the EU's Short Selling Regulation in the light of these arguments. It is suggested that although the provisions of the EU's Regulation introducing disclosure to the regulator are broadly sensible, as are the provisions designed to foster a stricter settlement regime, other provisions are more problematic and have the potential to cause damage to European financial markets.