Blood donations by populations from the Maghreb and Sub-Saharan Africa are a public health necessity for reasons of genetic polymorphism. This article aims to determine whether blood donors’ social characteristics – i.e. greater socio-economic integration and a strong sense of citizenship – constitute deterrents to blood donation among foreign populations. Results show that donors from the Maghreb and Sub-Saharan Africa are not better integrated than non-donors from the same areas. However, blood donors express a significantly greater sense of citizenship than non-donors. Donors from the Maghreb and Sub-Saharan Africa feel a greater sense of citizenship than non-donors from the same areas. The study of blood donation in these categories of population has two major implications. In biological terms, blood donation by foreign populations constitutes a response to transfusion needs. In cultural terms, blood donation is used by populations from the Maghreb and Sub-Saharan Africa as an active means of expressing their sense of citizenship.