He was born at Florence and became a magistrate in 1959. He was initially pretore in Florence and Milan, returning to his native city’s prosecution office in 1965. In 1991 he became Chief Prosecutor: his investigations included those on right-wing terrorism, the Train 904 bombing and the so-called Monster of Florence, as well as on the presence of mafia in Tuscany. Since 1992, he also acted a district antimafia prosecutor.
On 14 January 1997, Vigna was appointed as National Antimafia Prosecutor, a position he held until reaching age limits in 2005. He was succeeded by Piero Grasso. Vigna was honorary presidence of Magistratura Indipendente, a left-winged magistrate association.