In an eighteen year professional career, Negro amassed Serie A totals of 362 games and 24 goals, mainly for Lazio, winning eight major titles with the club, including one national championship and the 1999 Cup Winners' Cup. He also appeared with Italy at Euro 2000, where they finished in second place.
The following season, however, on 17 December 2000, Negro scored an own goal in a derby match against A.S. Roma, who eventually lifted the scudetto, while Lazio finished the season in third place.[8] During the 2003–04 season, Negro was able to capture his third Coppa Italia title with Lazio, beating Juventus in the final.[9]
Having joined A.C. Siena in 2005, Negro scored a dramatic 85th-minute goal to defeat former side Lazio 2–1 on the final day of the 2006–07 season.[10][11] Without it, Siena would have been relegated to the second division, instead of Chievo. He appeared a further 50 times in the league in two campaigns, for a total of 363 official games.
In August 2008, almost one year after retiring, 36-year-old Negro underwent a trial at Serie B club Modena FC, but nothing came of it.
On 16 November 1994, Negro made his debut for Italy, in a 2–1 home loss against Croatia in a UEFA Euro 1996qualifier. He received a total of eight caps with the Azzurri between 1994 and 2000, and he was selected by manager Dino Zoff to be a member of the Italian squad that took part at Euro 2000 tournament, where the national team reached the final, finishing the tournament in second place behind France.
Negro was a strong, aggressive, hard-tackling, physical player, who excelled in the air, and who possessed a powerful shot from distance. He was also a tactically intelligent, reliable, and versatile player, and disciplined defender, who excelled at zonal-marking. He was also an attentive man-marker, with reliable technique and distribution, as well as good pace and stamina, which allowed him to be effective when moving forward along the right flank after winning back possession.[13][14]
In June 2011, he passed the category 2 coaching exams, which made him eligible to coach Lega Pro teams.[15]
On 30 December 2010, Negro took his first coaching job, becoming the boss of Promozione amateurs Cerveteri, a team from Lazio with former experiences in the professional tiers of Italian football.[16] He left the club after only three months, resigning on 23 March 2011 due to poor results.[17] On 26 January 2012, Negro accepted a job offer as head coach of Serie D amateurs Zagarolo.[18]
On 5 January 2015, after Mark Iuliano's promotion as new head coach of Latina, Negro was appointed as a new youth coach for the club.[19]
In 2017 he became a youth coach for Cragnotti FC, a youth-only club founded by Massimo Cragnotti, son of former Lazio owner Sergio Cragnotti.
On 15 December 2021 he took on his first role as head coach in a professional club, joining Siena, with Franco Paleari as his assistant.[20] He left his role at Siena only two weeks later, on 29 December, following the appointment of Pasquale Padalino as new head coach.[21]
