The authors agree that this surname derives from a nickname originating in the appellative and occupational name Maestro (or, in Latinizing form, Magistro), which in turn continues the Latin magister magistri. The term covered several senses: from that of teacher to that of one who practises a trade or art, one who is expert in a given field, or one who occupies the role of chief or guide.

E. De Felice notes that on that Latin base the late and prestige forms Magistri(s) and Magistro were also modelled, and that in Neapolitan the appellative took the form maìsto. According to De Felice, the surname predominates in Liguria, Emilia-Romagna and Tuscany; the variant Maistri is proper to Veneto; Maisto corresponds to the Naples area, and Magistri is found in Lombardy and in central and southern Italy.