Silvio Fauner achieved his first significant result in the World Cup in December 1987 in the 30 km free technique and the first podium (3rd) in December 1991 in the 25 km classical technique. His first victory came in March 1991 victory in the relay in Lahti. During his career, his best result in the overall standings was the third place in the 1994-1995 season and also third in the sprint rating in 1996-1997. During his 20 years career in the World Cup he achieved 24 podiums including 5 wins (2 individual and three with the relay team and in the team sprint). He participated in four Winter Olympics (1992 - 2002), winning five medals. At six World Championships he took seven medals. At the 1994 Olympics he won the gold medal in the 4x10 km relay, with Fauner running the final leg and securing the victory against Bjørn Dæhlie in front of his Norwegian home crowd. Despite this victory, he regards as his greatest success winning the gold in the 50 km at the World Championships in 1995, equaling the achievement of his childhood idol Maurilio de Zolt. At other World Championships he won silver in the relay and bronze in the pursuit in 1993, silver in the individual pursuit and bronze in the relay, and two more bronze medals in the relay in 1997 and 1999, respectively. In the last years of his career, between 2003 and 2006, he participated exclusively in long distance races, mostly of Marathon Cup. Nationally, he had 24 podium rankings including 12 titles over various distances between 10 and 50 km.
Since 2007 Fauner is technical director of the Italian national team skiing, both male and female, replacing his former teammate Marco Albarello. Together with his teammates of the victorious 4x10 km relay of the 1994 Winter Olympics he was one of the torchbearers within the Olympic Stadium at the Opening Ceremony of the 2006 Winter Olympics. He was highly decorated, appointed Knight of the Order of Merit of the Italian Republic in 2007 and was awarded the Silver and Gold Cross of Merit of the Army. His older brother Aldo was also on the Italian team prior to Silvio but was diagnosed with an irregular heartbeat and was denied medical clearance to participate in the 1992 Winter Olympics.