The authors agree that the surname derives from a nickname based on the Latin term phalanga, which designated a roller or board of wood used to facilitate the transport of boats or very heavy objects. The nickname would have been related to the trade of the first bearer of the surname.

F. Miranda adds that the Latin term comes from the Greek phálaks-phálagos (φάλαγξ-αγγος), and that it also designated a lever placed between the boat and the land to load and unload vessels. He notes that the surname is spread in a good part of southern Italy, concentrated mainly in Campania, with presence also in Sicily and in other regions such as Lombardy, Lazio, Piedmont, Basilicata, Liguria, Tuscany, Emilia-Romagna, Calabria and Puglia.

E. Rossoni specifies specific zones of concentration: in the Naples area —Torre del Greco, Boscoreale, Pozzuoli, Boscotrecase, Pompei, Ercolano, Torre Annunziata and Casalnuovo di Napoli—, in the Salerno area —Scafati—, in Rome, in Gaeta —Latina area—, in Genzano di Lucania —Potenza area— and in Sicily, with presence in Palermo, Paternò, Catania, Messina, Taormina and Lipari. Rossoni also indicates that the surname Sfalanga would be the same form with an initial s- added, and records a specific nucleus in Gela, in the Caltanissetta area.