The authors agree that this surname originates in an occupational byname linked to a woman known for her craft skill. The form màstra is the equivalent of "mistress" in the sense of a woman qualified in a manual trade: seamstress, midwife, weaver or similar occupations. In time, that designation became a surname.

E. Rossoni specifies that mastra would be an archaic dialect form of the medieval Latin term magistra, and considers that these surnames could refer to the name or the figure of a founding ancestress who practised as a mistress of a trade. He notes two main cores: one in Molfetta, in the Bari area, and another, more substantial, in the Catania area, with a presence in Raddusa, Ramacca, Catania and Trecastagni. He also mentions the variant Lamastra, extremely rare, documented in the area between Potenza and Bari.

F. Miranda broadens the geographical distribution and indicates a presence in Lombardy, Piedmont, Tuscany, Apulia, Calabria and Liguria, as well as Sicily. In this last region, he records a diffusion in the Catania, Agrigento, Messina, Ragusa and Enna areas. V. Blunda stresses the specifically Sicilian character of the surname and highlights that the dialect word màstra was applied to women of recognized standing in their trade.