E. De Felice holds that the surname derives from a euphemistic alteration of the medieval nickname Pelavicino or Pelavicini, whose original meaning was offensive: "one who robs the neighbours; thief, usurer". This modification would have occurred between the 11th and 12th centuries. The founder of the great feudal family of the Pallavicini was Oberto I Pelavicino (died 1148); his grandson Oberto II is already cited both with the form Pelavicino and with that of Pallavicina.

E. Rossoni documents the form Pallavicinus from the year 1000, noting that the antipope Honorius II (1061–1072), Cadalus Pallavicinus, was named pope by the king of the Franks. In 1226 the Codex Pallavicinus was drawn up by the bishop Guglielmo Pallavicino; towards the end of the 15th century the lordship of Parma lands was exercised by the marquis Giovan Francesco Pallavicino; and in the second half of the 16th century Cyprianus Pallavicinus was archbishop of Genoa. Rossoni also records the interpretation of the pejorative medieval nickname, linking it to the Latin pelat vicinum, the equivalent of "thief or usurer". He notes that Pallavicini is typical of the Genoa and Alessandria areas, with a probably secondary area between the Pavia and Salerno areas, with a presence also in the Alessandria area.

R. Brondolo agrees on the base of the nickname pela vicini ("strips the neighbours"), applied to "greedy and overbearing people", without adding information on geographical distribution beyond northern Italy.