E. Rossoni notes that this surname is typical of the area comprising the provinces of Reggio Emilia, Modena, Bologna, Mantua and Ferrara. He also documents the variant Lugliengo, extremely rare and proper to western Piedmont, and Luglio, of a southern character, with a presence in Naples and Massa di Somma —in the province of Naples— and in Lauria, in the province of Potenza.

The authors agree that all these surnames derive from the birth of the founding ancestor in the month of July. F. De Laurentiis adds that it was already the custom among the Romans to give this name to children born in that month, which places the origin of the practice in classical antiquity.