National rules for family reunification take place in an increasingly transnational context. Social workers in Switzerland, whether they work in services for migrants or for elders, are confronted with requests for transnational family reunification with older parents. Such requests, while relatively rare, elicit responses which must be viewed as largely founded on professionals' values and norms regarding the care of elders, family cohabitation, the influence of cultural factors, and examined against a backdrop of increasing suspicion of motives for migration*especially in fields where migration issues have not been at the forefront of professional debate and practice. The militant stance of some services for migrants can thus be contrasted with the relative inexperience of professionals active in social services for elders, who rarely encounter recent migrants. The latter are more likely to reflect their own private*and unexamined*views when advising clients in a field characterised by complexity and instability. The authors interviewed social workers and families in two Swiss cantons. Their results point to ways in which distinct professional cultures could enrich each other and provide social workers with tools to critically analyse their own practice in a very difficult field, the contours of which remain largely unexplored.