Pillon moved his first footsteps into football with hometown team Pro Mogliano, before to join Juventus's youth ranks for three years. He then played mostly for Serie C1 and Serie C2 teams throughout his career, including a four-year spell at Padova and three seasons with Spezia. He spent his two last seasons as a player at Pro Mogliano.
Pillon started his coaching career in 1992 with amateur Interregionale team Salvarosa. He went on to become Bassano coach the next season before to join Treviso in 1994, leading them through three consecutive promotion from Interregionale to Serie B. In 1997 he left Treviso to accept an offer from Padova of Serie B in 1997, only to be sacked in a few weeks. This was followed by another unsuccessful spell at Genoa in 1998, before being appointed as Lumezzane boss during the 1999–2000 Serie C1 season. He returned to coach in the Serie B in 2000–01 as Pistoiese boss. In 2001–02 he led Ascoli to win the Serie C1 title, heading the bianconeri also in their successive Serie B campaign.
After starting the 2003–04 season without a job, he was appointed at the helm of Serie B team Bari on January 2004, leading the galletti out of the relegation zone.
During the summer of 2007, he was announced as new Treviso boss for their 2007–08 Serie B campaign in a third spell at the club for Pillon, with his brother Albino as assistant manager. This new experience however proved not to be as successful as it was initially expected, and Treviso found themselves in the bottom part of the table, escaping relegation in the final weeks of the season. On July 2008 Treviso announced to have agreed a mutual consent leave with Pillon.
On 16 December 2008 Pillon was announced as new head coach of Serie A relegation strugglers Reggina Calcio, being appointed as replacement for Nevio Orlandi, dismissed because of poor results with the amaranto. His tenure with Reggina however lasted just a month, being dismissed on 29 January 2009 due to poor results.
On November 2009 he was appointed head coach of Ascoli, a team he already coached from 2001 to 2003, replacing Alessandro Pane.
Pillon gained nationwide news after he was protagonist of a highly unusual fair play action during a Serie B league game versus Reggina: after his side questionably scored a goal while a Reggina player was lying injured on the pitch, he requested his players to allow the opponent team to score; the game then ended in a 3–1 home loss for Ascoli, and such choice was heatedly criticized by the local fans. The game events and his reactions, with Pillon defending his actions and declaring himself critical of the belligerent atmosphere in Italian football, were then cited as the reason for him being awarded the 2009 International Fair Play prize.
On June 2010 Pillon was announced as new head coach of recently-relegated Serie B club Livorno. Following an unimpressive first half of season, Pillon was relieved of his managerial duties on 14 February 2011 following a 0–1 loss to minnows Portogruaro.