Born in Dresden, Germany, as a child she spent some years in India and South America. She spent time there later as well, working as a clerk and a piano teacher, before borrowing enough money for the trip back to Germany. At the age of 26, she was able to secure a position as a soubrette at the Semper Opera in Dresden, but her talent soon outgrew this position. She later held positions at the Vienna State Opera, the Berlin State Opera, and the Deutsche Oper Berlin. She also gave concerts in Japan, America, and Australia. In her discography are complete recordings of Die Zauberflöte (as the Queen of Night, conducted by Sir Thomas Beecham, 1937-38, for EMI) and Rigoletto (with Jan Peerce and Leonard Warren, conducted by Renato Cellini, 1950, which was RCA Victor's first complete opera recording done in America for commercial release).
Berger appeared at the Metropolitan Opera in the 1949-50 and 1950-51 seasons, in Der Rosenkavalier (opposite Eleanor Steber and Risë Stevens, conducted by Fritz Reiner and directed by Herbert Graf), Rigoletto (with Warren, then Enzo Mascherini), Die Zauberflöte, and Il barbiere di Siviglia (with Giuseppe Valdengo). She also sang Woglinde and the Waldvogel in Der Ring des Nibelungen, with Kirsten Flagstad and Helen Traubel alternating as Brünnhilde.
At 60 years of age, she took her leave of the stage and taught as a professor in Hamburg and Essen, where she died in 1990. In 1992, the Bästleinstraße in Dresden was renamed the Erna-Berger-Straße in her honour.