After returning to the United States, Chookasian was approached by Rudolf Bing again to join the roster at the Metropolitan Opera. This time she relented and made her debut with the company on March 9, 1962 as La Cieca in Ponchielli's "La Gioconda" with Zinka Milanov in the title role, Franco Corelli as Enzo, Nell Rankin as Laura, Robert Merrill as Barnaba, Giorgio Tozzi as Alvise, and Fausto Cleva conducting. During the performance Francis Robinson, then assistant general manager at the Met, had the house phones hooked up so Rosa Ponselle could hear Chookasian's entrance over the telephone at her home. Ponselle, who had developed a strong personal friendship with Chookasian as well as being her opera mentor, recalled "It not only brought back such wonderful memories, but it was another Force of Destiny." The audience and the critics responded enthusiastically to her performance. Paul Henry Lang wrote in his review that "From what we heard last night, we may predict a splendid career for the young lady from Chicago." This was the beginning of a more than two decade long career at the Met, during which time Chookasian was coached privately with Armen Boyajian.