E. De Felice identifies this surname as Lombard, very frequent in Milan in the form with -zz-, the variant with -cc- being an old graphic alternative. According to De Felice, it derives from the place name Cazzaniga, documented for two localities: Maleo, in the Lodi area, and Merate, in the Como area.

This surname could be related to Gazzaniga, in the Bergamo area, and gathers the proposal of the scholar Olivieri, who derives it from the dialectal term gazza, with the sense of "prohibited wood". An alternative hypothesis is also mentioned that connects it with a sequence of Roman personal names: Cattius, Cattanius and finally Cazzaniga, that is, its transformation into a surname. This source documents its presence in Milan from the 15th century, in the register of the merchants of fine wool, and in the Brianza around 1456, in the locality of Colzano.