The paper offers a theoretically grounded analysis of international postgraduate students' perspectives on the importance and development of global citizenship knowledge and competences while they are studying, and how these are valued and enacted afterwards. It draws on a series of interviews with non-Western international postgraduates during their studies in the UK and upon return to their home countries. It uses the concepts of social and cultural cosmopolitan competences as a framework to discuss the perceived benefits of educational mobility, and the possibilities and limits of social connectedness and openness in the internationalised university environment.