Abstract : One-third of those interviewed for the Trajectories and Origins survey agreed that "to be accepted in France you have to forget your origins". This reflects the assimilationist idea that to integrate, immigrants and their descendants must break their ties with their country of origin. On the other hand co-development policies, currently enjoying a boom in France and the European Union, seek to make migrants the chief players in developing their home countries' economies. Caught between these contradictory pressures immigrants must choose between here and back there. What can be said today of transnational practices among immigrants living in metropolitan France?