E. Rossoni places the main origin of this surname in the south of Sardinia, with presence concentrated in the Cagliari area and in the Carbonia area, and additional clusters in Rome, in Bari and in Calabria. He notes that in Sardinian, both in the Logudorese and in the Campidanese variant, cara means "face, countenance, expression", without relation to the equivalent Italian adjective. Rossoni documents the surname in medieval Sardinian sources, among them the signatories of the Peace of Eleonora of 1388 and the Condaghe of Santa Maria di Bonarcado (11th to 13th centuries). In some cases it derives from the Latin name Cara or from the Gens Caria, and in others from toponymy.

V. Blunda proposes, on the other hand, a Greek origin from Caràs, a personal name preserved in the Byzantine transmission of southern Italy. According to this author, the Sicilian surname fixes the Italianised spelling of that original name, and the variant Carasi would represent a graphic adaptation of the same etymon.