The authors differ as to the origin of the surname. E. Rossoni proposes a derivation from the Germanic given name Riso, Risonis, documented in the Codex Cavensis in the year 900 and in Sessa Aurunca, in the Caserta area, during the 12th century. R. Brondolo, on the other hand, holds that the surname comes from (Pa)risi, a medieval form of Parigi (Paris), which would indicate provenance from or relation with that city, and also notes a possible link with the medieval epic.

As to the geographic distribution, Rossoni indicates that Risi is widely diffused, with a presence in the Milan area, in the Verona area, in the Bologna area, in the Tyrrhenian strip between Rome and Salerno, and in the Salento area —that is, the southernmost zone of the region of Apulia, in southern Italy. The form Riso has stocks in the Salento, in the Naples area, in the Reggio Calabria area and in Sicily. Risino seems proper to Sicily, with a presence in the Catania and Syracuse areas. Brondolo places the surname preferentially in northern Italy.