This paper discusses the relationship between internationalisation, mobility, quality and equality in the context of recent developments in research policy in the European Research Area (ERA). Although these developments are specifically concerned with the growth of research capacity at European level, the issues raised have much broader relevance to those concerned with research policy and highly skilled mobility. The paper draws on a wealth of recent research examining the relationship between mobility and career progression with particular reference to a recently (...) completed empirical study of doctoral mobility in the social sciences (Ackers et al. Doctoral Mobility in the Social Sciences. Report to the NORFACE ERA-Network, 2007). The paper is structured as follows. The first section introduces recent policy developments including the European Charter for Researchers and Code of Conduct for the Recruitment of Researchers and the European Commission’s Green Paper on the ERA. The discussion focuses on concerns around the definition of ‘mobility’ and the tendency (in both policy circles and academic research) to conflate different forms of mobility and to equate these with notions of excellence or quality. Scientific mobility is shaped as much by ‘push’ factors (limited opportunity) as it is by the ‘draw’ of excellence. Scientists are exercising a degree of ‘choice’ within a specific and individualised framework of constraints. The following sections consider some of the ‘professional’ and ‘personal’ factors shaping scientific mobility and the influence that these have on the relationship between mobility, internationalisation and excellence. The paper concludes that mobility is not an outcome in its own right and must not be treated as such (as an implicit indicator of internationalisation). To do so contributes to differential opportunity in scientific labour markets reducing both efficiency and equality. (shrink)