The authors agree that this surname derives from a dialect byname based on the Sicilian term pajno, referring to a vain and frivolous person, but very concerned with elegance and appearance. E. Rossoni adds a second hypothesis: it could also be a contraction of Paglino, a diminutive form of the name Paglia.

As for the geographical distribution, Rossoni notes a presence of the surname in the Naples area and at Torre del Greco, as well as in various points of Sicily —the island of Lipari, Agrigento, Messina, Catania and Palermo— and at Condofuri, in the Reggio Calabria area. F. Miranda specifies that the variant Pajno is concentrated mainly in Sicily, in the Messina areas —including Lipari, Saponara and Patti— and Palermo, with a presence also in the Enna area, at Centuripe. Miranda adds that there are specific areas of this surname in other regions: Lombardy, Piedmont, Veneto, Calabria and the Marche.