E. Rossoni proposes a French origin for this surname: it would derive from the medieval French term fruster or frustier, which designated a carpenter or cabinetmaker. He also does not rule out that it may come from the Provençal surname Fruster or Frustier, with the same sense. Rossoni notes that the surname is peculiar to Sicily, with presence in Palermo, in Sant'Agata di Militello and Longi in the Messina area, and in Trapani and Erice in the Trapani area. The variant Frustieri, also Sicilian and of the Palermo area, is extremely rare.

V. Blunda proposes, on the other hand, a Sicilian dialectal origin: the surname would derive from the word frustèri, which in the local dialect means "stranger" or "foreigner". The term designated the one who arrived from another land and was received by the rural community with the habitual mixture of curiosity and reserve. As a surname, it would have arisen from the identification of an ancestor who settled in a Sicilian village coming from another region. Blunda links this surname with Furitano, of similar sense.

Both authors agree on the Sicilian localisation of the surname, but differ in its etymology: while Rossoni points to a trade of French or Provençal origin, Blunda explains it as a dialectal gentilic referring to the foreign origin of an ancestor.