She was first based in Switzerland, where she received international attention when she appeared in the first performance in German of Menotti's The Consul, in Basel, in 1951.

[9] In 1951 she sang the role of Magda in the first German-language performance of Menotti's The Consul in Basel, leading to international recognition.

[8] In the same year she performed at the Edinburgh Festival in the Hamburg State Opera's production of Beethoven's Fidelio,[2] as Leonore, with Lisa Della Casa as Marzelline.

Inge Borkh is splendid: in figure and dress she has more verisimilitude than most sopranos can command … she sings with freedom and ardour; she is Beethoven's idea incarnate".

[10] After this Borkh performed at major opera houses in Europe, in Hamburg, Stuttgart, Barcelona, Lisbon, London, Milan and Naples, among others.

"[1] In 1954, Borkh appeared in Rio de Janeiro;[9] in the same year she performed at the Florence Maggio Musicale as Eglantine in Weber's Euryanthe, conducted by Carlo Maria Giulini, and in 1955 at the Salzburg Festival, as Cathleen in the premiere of Egk's Irische Legende.

[9] In 1956 she played the role of Queen Elizabeth in the American premiere of Britten's Gloriana, conducted by Josef Krips, who along with Fritz Reiner was one of her favourite conductors.

It would have been earlier, but the manager of the house, Rudolf Bing, wanted her to play the title role in Salome, which she repeatedly declined to do.

In the same season she played Sieglinde, and in 1971 she alternated with Christa Ludwig as the Dyer's Wife in Die Frau ohne Schatten.

[13] In a retrospective study of her career published in Opera News in 2001, the critic Martin Bernheimer wrote: Even when portraying monstrous heroism, lust or misery, she somehow managed to exude the quality we used to label femininity, not to mention generosity and an innate humanity.

The complete works include Egk's Irische Legende, Gluck's Iphigénie, and Salome and Elektra, both conducted by Mitropoulos.

[18] The complete Turandot was recorded for Decca, conducted by Alberto Erede, alongside Mario del Monaco, Renata Tebaldi and Nicola Zaccaria.

[19] Borkh can be heard on CD performing Scenes from Elektra and Salome, conducted by Reiner in the 1950s (RCA Victor 09026 68636-2).

[21] She took part in a 1961 recording of Beethoven's symphonies with the Royal Philharmonic Orchestra, conducted by René Leibowitz, performing the soprano solo in the Ninth alongside Ruth Siewert, Richard Lewis and Ludwig Weber.