On June 23, 2016, the United Kingdom held a referendum on its continued membership of the European Union and, as you know, the British voted to leave. We now face a number of issues of crucial constitutional importance that will affect not only relations between countries, but also businesses and individuals in a more direct and tangible way. At this initial stage, I intend to address two major questions in particular. First, what are the direct and immediate legal effects of the referendum result itself? If the British had voted to remain, it would have meant that a reform of the EU would have been initiated that would also have greatly benefited Sweden. Is it possible to save and use some of the legal instruments that this reform would have entailed in order to develop and make the EU more effective? Secondly, how should Article 50 of the Treaty on European Union, which governs the withdrawal of a Member State from the EU, be interpreted and what complications does this article entail? This article raises a number of legal issues of considerable constitutional importance that directly affect both businesses and individuals in all EU Member States. My work on these issues will also inform future research on the UK's relationship with the EU.