The authors differ on the origin of the surname. E. Rossoni proposes that it would derive from the medieval name Cafarus or Caffarus, documented between the 11th and 12th centuries with the sailor, crusader and consul of Genoa Caffarus de Caschifellone, mentioned in the Genoese Annals from 1099 to 1163. For the southern forms of Italy, Rossoni adds two other possibilities: a nickname based on the Arabic word kaafir, meaning "infidel", or on the Calabrian and Sicilian adjective càfaru, meaning "moth-eaten" or "worm-eaten".

P. Durante, on the other hand, proposes a Greek origin, interpreting it as a proper name, although without developing the hypothesis in greater detail.

As for its geographical distribution, Rossoni notes presence in coastal Campania, Basilicata, Puglia —with greater concentration in the Salerno and Bari areas—, Lazio, Sicily —especially in the Messina and Palermo areas— and the Turin area. The variant Caffarri is recorded in the Reggio Emilia area.