The article describes the European Union’s main achievements on communitarian regulation of corporate law. Specifically, two basic aspects of EU corporate law will be addressed. On one hand, European companies have the freedom of establishment, which means that they have the right to operate internationally in equal conditions with respect to national companies. On the other, EU law has tried to achieve two objects on corporate regulation: uniformity and harmonization. Uniformity can be reached by Regulations, i.e. the emblematic case of the Societas Europea (SE) or the European Economic Interest Grouping (EEIG). When political compromise didn’t allow European Institution to uniform, they used Directives with the aim of harmonize some pivotal aspects of the regulation of a company, especially if it operates cross-border. An example can be the cross-border mergers, which often could not be set under national legislation before the implementation of the 2005 Directive on the matter. Uniformity in EU corporate law will be highlighted in the article.