The authors agree that this surname derives from the name Francesco, formed in the Late Middle Ages as a nickname and ethnic determinative from the adjective francesco, with the sense of "French; citizen, inhabitant or native of France", documented already in the 11th and 12th centuries. E. De Felice notes that the name reaffirmed itself and became very frequent towards the middle of the 13th century through the prestige and the cult of Saint Francis of Assisi, at which point it lost its ethnic value to acquire a religious character.

V. Blunda proposes a complementary perspective for Sicily: he traces the origin to the Germanic frank, with the sense of "Frank, belonging to the people of the Franks", to which the Germanic adjectival suffix -isk —the same that gave the Italian -esco— was added to form Frankisk. According to Blunda, the surname spread in medieval Italy through the political and cultural influence of the Franks in the peninsula, especially from the Carolingian period.

F. De Laurentiis highlights that the surname is widely spread throughout Italy, although it is especially peculiar to the south and, in part, to Liguria, where patronymic forms with the prepositions De or Di appear.