Rubuta ci gaba don wannan sakin layi - Théodore ya taka leda a manyan matasa a Quebec Major Junior Hockey League (QMJHL), inda ya lashe kofin shugaban kasa a matsayin zakarun QMJHL kuma ya yi gasa a gasar tunawa da gasar tare da Hull Olympiques a 1995. Ya lashe kofin Ford a matsayin babban dan wasan tsaron gida da Guy Lafleur Trophy a matsayin MVP na wasan kwaikwayo a 1995 kuma ya kasance sau biyu na QMJHL na biyu All-Star. Canadiens sun zaba shi a matsayin na 44 a shekara ta 1994
, Théodore ya buga wasanni takwas a Montreal, inda ya lashe Vezina da Hart trophies, duka a shekara ta 2002. A shekara ta 2006, an canza shi zuwa Colorado Avalanche, inda ya buga cikakkun yanayi biyu. Théodore kuma ya buga wasanni biyu don Washington Capitals. A matakin kasa da kasa, Théodore ya lashe lambar zinare tare da Kanada a gasar zakarun duniya ta matasa ta 1996, inda aka nada shi mafi kyawun mai tsaron raga a gasar. Ya kuma fara Kanada a Gasar Cin Kofin Duniya ta 2001 kuma ya kasance madadin gasar cin kofin duniya ta 2004.