Surnames of grandparents were collected from children in the primary schools of the Albanian-Italian, Croat-Italian and Greek-Italian villages of southern Italy and Sicily. The coefficients of relationships by isonymy show almost no relationship with ethnicity. Ethnolinguistic minorities of southern Italy and Sicily are geographically subdivided into two main clusters: the first cluster comprises the Albanian, Croat and Greek communities of the Adriatic area; and the second cluster comprises the Albanian and Greek communities of the Ionian, Thirrenian and Sicilian areas.