In the mid-1950s, Serri was in charge of the Reggio Emilia Province in the Italian Communist Youth Federation.

[1] In the seventies he became regional secretary of the PCI in Veneto and in 1979 he entered the Chamber of Deputies.

He opposed the dissolution of the PCI and February 3, 1991, became one of the founding fathers of Rifondazione Comunista; in 1995 that group became pasrt of the Movement of Unitarian Communists (MCU).

Here he dealt mainly with the countries of the Horn of Africa, In 2000 he was a mediator on behalf of the European Union to reconcile Ethiopia and Eritrea, which would happen with the Algiers Agreement.

From 1984 to 1989, he also held the position of national president of the Associazione Ricreativa e Culturale Italiana (ARCI).