In this paper, we investigate the impact of membership in the Bologna Process on patterns and driving forces of cross-national student mobility. Student exchange flows are analyzed for almost all Bologna Process member states and non-Bologna OECD members over a ten-year period (from 2000 to 2010). We apply a social network approach focusing on outbound diploma mobility. Based on social network analyses, we first visualize the exchange patterns between sampled countries. In doing so, we analyze the student exchange linkages to gain descriptive insights into the development of the network. Second, we use exponential random graph models (ERGM) to test which factors determine transnational student mobility. The results of our network analyses reveal that cross-national student exchange networks are stable over time. At the core of these networks are the USA, Great Britain, France, and Germany; they attract highest shares of students from most remaining countries in our sample. Moreover, the results of the ERGM demonstrate that homophily between countries determines student exchange patterns. The most relevant ties exist between bordering countries. Moreover, membership in the Bologna Process impacts on mobility patterns, and the effect size increases over the periods investigated.