She sings grueling roles like Abigaille, Lady Macbeth or Turandot as well as lighter pieces like Giordano's Maddalena, Cio-Cio San (Madama Butterfly), or Verdi's Desdemona at major opera houses around the world.
She attended master classes of Cathy Berberian, Galina Vishnevskaya, Gino Bechi, Paul von Schilawsky in Florence and Montpellier, Giuseppe Di Stefano, who later chose her to perform a concert with him at Théâtre du Châtelet.
A few months later followed her debuts in Nabucco at Covent Garden Opera, Madama Butterfly in Naples and Venice (La Fenice) and in Don Carlo at Royal Albert Hall in London.
The year 2001 brought her to the Lyric Opera of Chicago as Tosca, to Madrid with Verdi's Requiem, to Brussels (Théâtre de la Monnaie) with Antonio Pappano and Zürich with Macbeth, to Berlin in the title part of Aida and to Macerata with Norma.
The engagements of the 2004-05 season included, among others, Salome in Braunschweig and Athens with the Vienna Philharmonic Orchestra, as well as in Rome with the Orchestra dell'Accademia Nazionale di Santa Cecilia and in Tokyo; Nabucco and Fedora at the Vienna State Opera; Tosca in Zürich with Nello Santi, at the New York Metropolitan Opera with James Conlon, and in Washington, D.C.; Verdi's Aida at the Thermae of Caracalla in Rome, directed by Plácido Domingo, concluded the season.
After the great successes gained with Puccini's La fanciulla del West and Giordano's Andrea Chénier at the Deutsche Oper Berlin in September and October 2006, Valayre's engagements in 2006-07 also included Nabucco at the Opera House of Zürich, Manon Lescaut at Miami's Florida Grand Opera, Macbeth at the Staatsoper Unter den Linden in Berlin and her role debut as Desdemona in Verdi's Otello at the Beethoven Festival in Warsaw.
In August 2008, she could be heard in Richard Strauss´ Four Last Songs and Ludwig van Beethoven's 9th Symphony at Šaľa São Paulo, in Brazil, as part of the Cultura Artística International Series.
In the 2008-09 season, Sylvie Valayre could be heard frequently throughout Germany, among others at Semperoper Dresden and Staatsoper Berlin in Macbeth and Turandot as well as at Oper Leipzig in Peter Konwitschny's new production of Giuseppe Verdi's Aida.
In 2009–10, she returned to San Diego Opera for Nabucco, to Oper Leipzig for Aida, to Staatsoper Berlin for Tosca and gave her role debut as Odabella in Verdi's Attila in Marseille.