Pizzinato joined both the Italian General Confederation of Labour and the Italian Communist Party in 1947 and went to study Economy and Sociology at the Moscow State University, though he didn't graduate since he only had the Primary school diploma.

[1] Once he returned to Italy in 1961, Pizzinato began his career in the CGIL, being appointed Secretary-general of the trade union in March 1986.

Again in 1996, Pizzinato was appointed undersecretary at the Ministry of Labour during the Prodi I Cabinet.

In 2007, Pizzinato, being contrary to the birth of the Democratic Party, adhered to Fabio Mussi's motion to leave the Democrats of the Left[6] and join, a few years later, Left Ecology Freedom.

[7] Since 2007, Pizzinato is president of the Lombardy section of the National Association of Italian Partisans.