A popular abbot at St. Paul's Outside the Walls, one of the most popular churches in Rome, he was defrocked by Pope Paul VI, with whom he had feuded over theology, during the Cold War, after he had announced his intention to vote for the Italian Communist Party in 1976, which Franzoni had joined in June of that year.
Franzoni opposed the initiated beatification process for Pope John Paul II. In 2005, Franzoni joined ten other dissident theologians to appeal to Catholics critical of the canonization process to voice their concerns.
- La terra è di Dio (1973);
- Omelie a S. Paolo fuori le mura (1974);
- Il posto della fede (1977);
- Il diavolo mio fratello (1986);
- Le tentazioni di Cristo (1990);
- La solitudine del samaritano (1993);
- Farete riposare la terra (1996);
- Giobbe, l'ultima tentazione (1998);
- Lo strappo nel cielo di carta (1999);
- Anche il cielo è di Dio (2000);
- Ofelia e le altre (2001);
- La morte condivisa (2002);
- Del rigore e della misericordia (2005)
- "Pope Defrocks Priest". Ellensburg Daily Record. 5 August 1976. P. 6. GoogleNews. Retrieved 21 July 2009.
- "Giovanni FRANZONI (1928-vivente)" Donne e uomini di pace — viventi. PeaceLink. Retrieved 21 July 2009. (in Italian)
- Pullella, Phillip. "Don't Make John Paul Saint: Dissident Theologians". redOrbit. 6 December 2005. Retrieved 23 July 2009.
- Magister, Sandro. "Turnover at St. Paul's Outside the Walls: Here Come the Monks from the Countryside". Trans. Matthew Sherry. Chiesa News. 9 March 2004. Retrieved 21 July 2009.