Since 1990, the temporary labour migration of ethnic Hungarians from the Transylvanian region of Romania has provided a context for the emergence of new and distinctly national modes of self-understanding. In this paper I develop a three-part analytical framework to examine the ways in which migration is conducive to the transformation and dissemination of changing national identities. First, I argue that host countries for all migrants (including those involved in other examples of ethnic affinity migration) are inevitably recognised as foreign and often alienating. Second, I examine the reasons migrants consistently understand and represent these new-found differences in explicitly national terms. Finally, I discuss the ways in which migration networks facilitate the standardisation and diffusion of transformed identities. Rather than signalling the demise of national forms of identification predicted by some observers of international migration, the Transylvanian Hungarian case reveals how temporary labour migration can be the conduit for the transformation and reinvigoration of national identities.