Two of his most important victories reach him at two stages of the Vuelta a España in 2001 and 2003. During his first Vueltaetappensieg Filippo Simeoni stopped short of the finish line and was carrying his bike over her, one hand in the memory of the victims of the terrorist attacks on 11 September 2001, on the other hand to the face of a pending doping suspension - express his love and his hatred for the sport of cycling - as he put it. The International Cycling Union ( UCI) punished him for it with a fine.
Simeoni was a client of the controversial physician Michele Ferrari, who oversaw a variety of athletes, including Lance Armstrong. In the context of government investigations in the so-called "Ferrara " case, he testified in court that he had used since 1993 doping and that Ferrari have prepared him with agents such as EPO and growth hormones in 1996 and 1997 and instructed him how the funds are to use. 2001 and 2002, Simeoni was excluded for six months for doping of all competitions. Armstrong called Simeoni in an interview with the French newspaper Le Monde in July 2003, a liar. Simeoni, Armstrong sued for libel and demanded 100,000 euros. He stated that he was to receive money, he would donate it to charity. The suit was dismissed, however, in January 2006 by a Paris court.
In the 18th stage of the Tour de France 2004 Simeoni made an attempt to join a breakaway group of six riders. Although none of the drivers Armstrong vulnerable lead in the overall standings, followed Armstrong Simeoni, Armstrong's why rival shots from the T-Mobile team pursuit. This saw the six leaders threatened their chances of a stage victory. They urged Armstrong to fall back to the peloton, but Armstrong did not begrudge Simeoni unsuccessful and fell back only when this it did. Armstrong later made a derogatory gesture and said, Simeoni do not deserve to win a stage. Two days later, on the last stage, in which normally is driven slowly and celebrate the leaders in the ratings their victories - 2004, Armstrong in the overall standings - attacked Simeoni again and again, to take revenge for the humiliation, but Armstrong's team caught up with him every time a.
Since Simeoni at the time of the events of the 2004 tour was a prosecution witness in the trial against Ferrari, Italian authorities threatened to take up investigation of witness intimidation against Armstrong. In March 2005, Armstrong was questioned. Armstrong was accused by Italian authorities in December 2005 and had to answer charges of defamation Simeonis on 7 March 2006. In April 2006, the charges were dropped.
29 June 2008 Filippo Simeoni won the Italian road championship of professional cyclists in Bergamo. From a top flight out, he attacked a few kilometers from the finish and won by a narrow margin against Giovanni Visconti, Filippo Pozzato and Davide Rebellin.
At the end of the 2009 season Simeoni ended his career as a professional cyclist.