Many believe that social capital fosters the accumulation of human capital. Yet international university students arrive in their host country generally denuded of social capital and confronted by unfamiliar cultural and educational institutions. This study investigates how, and to what extent, international students renew their social networks, and whether such investments are positively associated with academic performance. We adopt a social capital framework and conduct a survey of international students at a typical Australian university in order to categorise and measure investments in social capital renewal, and test a multivariate model of academic performance that includes social capital variables, amongst others, as regressors. Our survey results reveal a high degree of variability in social capital investment across students and, amongst the more active, a tendency to build close networks in the main with students from their own country of origin. Our empirical results suggest that such investments are not associated with improved academic performance but are associated with increased well being.