E. Rossoni notes that the origin of the surname is uncertain and proposes several hypotheses. The Sicilian clusters could derive from nicknames related to the dialectal word caiola ("cage"); the cluster of the Mantua area could derive from the place name Caiolo, a locality of the Sondrio area. Rossoni also considers possible, for all the variants of the surname, a derivation from the diminutive Caiolus of the Latin gentilic name Caius.

V. Blunda offers a different reading focused on Sicily: he links the surname to the dialectal word cajola, meaning "hairnet of silk or thread", a habitual female accessory on the island during the modern period. As a surname it could have originated in the trade of the weaver or seller of these accessories. Blunda notes that Sicilian onomastics has several surnames linked to female headdress, such as Bannò or Birriola.

Both sources agree on the presence of the surname in Sicily and on its relation to the dialectal word caiola, although they differ in its meaning: Rossoni interprets it as "cage", while Blunda links it specifically to a hair accessory.