In 1967 Vallée represented Belgium in the Festival of Rio, where Jacques Brel was a member of the jury. He represented Belgium for the Eurovision Song Contest 1970 with "Viens l'oublier" finishing eighth. He participated a second time in the Eurovision Song Contest 1978 with "L'amour ça fait chanter la vie", ending up second behind the Israeli entry. At the time, it was Belgium's best ever Eurovision finish.