In 1949, she made her first appearance in the Paris Opéra as Marguerite. The following year, she made her debut in Salzburg and at the Royal Opera House, Covent Garden as Mimì, and in the United States with a recital at Carnegie Hall. In March 1951, she made her Metropolitan Opera debut in New York as Marguérite, and she went on to sing with the company for ten years. In 1952, she became an instant favourite in Buenos Aires at the Teatro Colón as the title role in "Madama Butterfly". She returned to Buenos Aires many times until 1979. She sang at La Scala in Milan from 1950 to 1956 and, in 1957, she sang at the Vienna State Opera.