The authors agree that this surname is a compound of the personal names Giovanni and Greco, used in the Middle Ages also as a given name, which in time became a surname from the name of the founding ancestor of the lineage.

F. Miranda specifies that the surname belongs to the category of patronymics formed with the shortened forms of Giovanni and its old variants: Johannes, Ianni, Zanni. As examples of the same type he cites surnames such as Iannuzzo, Giammarrone ("Giovanni Marrone"), Iannibelli ("Giovanni the Handsome") or Iagrossi ("Giovanni the Fat").

E. Rossoni notes that the surname is very widespread in Sicily, in the Salento area —that is, the southernmost zone of the region of Puglia, in southern Italy— and between the Potenza and Cosenza areas. Miranda adds that its presence in Sicily is predominant, with concentrations in the Catania, Agrigento, Palermo, Syracuse and Caltanissetta areas and in the Enna area, and that outside the island the surname appears in Apulia —the Lecce area—, Lazio, Lombardy, Piedmont, Liguria, Veneto, Emilia-Romagna, Basilicata, Calabria, Tuscany and Campania.