This article looks at the determinants of the political integration of migrants at the local level, focusing on two dimensions of political integration: political interest (attitudinal dimension) and political participation (behavioral dimension). Based on a representative survey among Italians, Kosovars, and Turks in the city of Zurich, we tested the thesis advanced by the social capital approach which posits a link between membership in voluntary associations and political integration. Our findings suggest that membership in voluntary associations favors the political integration of the three groups under investigation. Furthermore, we find an impact of both ethnic and cross- ethnic membership. However, while the effect of associational involvement on the behavioral dimension of political integration is strong and consistent across national groups, the attitudinal dimension displays a weaker and differential impact. Political attitudes and socio-demographic characteristics play a less important role, except for the effect of the former on political interest, and also tend to have a differential impact on the three groups.