The theoretical arguments in favor and against citations to foreign courts have reached a high degree of sophistication. Yet, this debate is often based on merely anecdotal assumptions as to their actual purpose. This Article aims to fill this gap in the literature. It offers quantitative evidence from ten European supreme courts in order to assess the desirability of such cross-citations. In addition, it examines individual cases qualitatively, developing a taxonomy of cross-citations based on the degree to which courts engage with foreign law. The Article highlights the often superficial nature of cross-citations in some courts. Yet, by and large, our analysis supports the use of cross-citations: it does not have the pernicious effects sometimes suggested by critics, such as undercutting national sovereignty or the legitimacy of the legal system. At best, cross-citations provide a source of inspiration to interpret national law. At worst, they are largely ornamental and of marginal help to make a particular policy argument more persuasive.