Between 1820 and 1929, in Iggio and in Tiola, rural parishes not too distant from the respective chief towns, a large number of marriages occurred between natives and former foundlings. The study of the distribution of surnames within the provinces of Emilia-Romagna (Italy) leads one to believe that the phenomenon was quite widespread in this region. This kind of marriage caused a direct gene flow from the town centres to the adjacent hilly areas. In general, however, the flow does not appear to have been so high as to change remarkably the genetic structure of the populations involved in the reception of the former foundlings, regardless that a percentage of them were taken to the hospitals of the towns from the countryside, and that many of those effectively born in the cities were children of people whose genetic pool did not differ substantially from that of the residents of the adjacent hilly zones.