Following the unification of Italy in 1861, a reorganization of the internal subdivisions of the country ensued. By decree of 17 March 1869, the comuni of Paderno, Dugnano, Incirano, Cassina Amata, and Palazzolo Milanese were fused into a new comune called Paderno Milanese.
Other names for the comune were proposed (including Padergnano and Borgosole) through the 1880s.
By decree of 1 February 1886, the comune's name was formally changed to the current name of Paderno Dugnano.
Paderno Dugnano received the honorary title of city with a presidential decree on 25 September 1989.