Graduated in Political Science and International Relations at the University of Florence (1988), Pistelli started his political career in the Christian Democracy ("Democrazia Cristiana") as Responsible for the foreign affairs office of the Christian Democrat Youth Movement (1987–1991) becoming, in the following years, Member of the secretariat and directorate (1995–1999) and coordinator of the national secretariat (1999–2001) of the Italian People's Party ("Partito Popolare"), and member of the executive and official responsible for foreign affairs (2001–2004) of the Democracy is Freedom – The Daisy ("La Margherita") party.