Immigrant associations are increasingly, at least in Italy, key actors in the integration of foreign populations into local society; integration understood not as assimilation but as construction of a dialogue that, while respecting mutual differences, can enrich immigrants as much as natives. Not by chance, the objectives pursued most frequently by immigrant associations are both integration and the promotion of the specific culture of the populations (and countries) of which they are expressions. On the one hand, therefore, immigrant associations seek to interrelate their members, and in general the communities which they represent, with the population and culture of the host country. On the other hand, however, these same associations increasingly seek to maintain and build relationships between immigrant communities and their countries of origin, thereby becoming transnational actors. In this regard, immigrant associations sometimes promote projects and initiatives to foster the development of specific areas of their countries of origin, fuelling a process which has been termed co-development. Moreover, co-development may be an occasion to activate or consolidate collaboration among immigrant associations and other organizations in the host country. The paper analyses the topics just outline on the basis of data collected by a research project on the associations of Peruvian citizens in Lombardy.