While under contract with Metro-Goldwyn-Mayer from 1933 to 1937, Viertel co-wrote the scripts for many movies, particularly those starring her close friend Greta Garbo, including Queen Christina (1933) and Anna Karenina (1935).

[1] Viertel was born Salomea Sara Steuermann in Sambor, a city then in the province of Galicia,[2] which was a part of the Austro-Hungarian Empire, but today is in western Ukraine.

Her mother, Auguste (née Amster) Steuermann, taught the importance of hospitality, which Salka adopted during her years in exile in Santa Monica, California.

[3] Her siblings were Eduard, a composer and pianist; Zygmunt, a Polish national football player who perished in the Holocaust; and Rosa (1891–1972), married from 1922 until her death to the actor and director Josef Gielen.

[4] After debuting as Salome Steuermann at the Pressburg Stadttheater (regional theater), Salka earned starring roles in Germany and Austria before and during World War I.

Murnau's instigation, the Viertel family emigrated to Hollywood when Berthold received a contract with Fox Film Corporation as a director and writer.

She agreed with Max Reinhardt (whom the Viertels encountered in New York on their way to Los Angeles)[2] that she was "neither beautiful nor young enough" for a career in movies, which she was attempting to begin at age forty.

The Viertel home became the site of salons and meetings of the émigré community of European intellectuals along with Hollywood luminaries, particularly at Sunday night tea parties that Salka hosted.

[1] Her assortment of regular guests included not only Sergei Eisenstein, Charlie Chaplin, Christopher Isherwood (who moved into Viertel's garage apartment with his boyfriend in 1946[8]), Hanns Eisler, Bertolt Brecht, Max Reinhardt, Bruno Walter, Lion Feuchtwanger, Franz Werfel, and Thomas Mann, but could range all the way from Arnold Schoenberg to Ava Gardner.

[1] Besides acting as a diplomat within the ethnically and politically diverse expatriate colony, Viertel also played a practical role as a go-between who could accelerate projects and careers.

[2] In the fight against Nazism, Viertel came to the aid of those trapped in Europe,[16] in part by serving as a founding member of the European Film Fund,[2] which brokered contracts with Hollywood studios.

Through the Fund's assistance, notable artists such as Leonhard Frank, Heinrich Mann, Alfred Polgar, Walter Mehring, and Friedrich Torberg received emergency visas that enabled them to escape the Nazis.

With the onset of the Cold War and McCarthy era, Viertel was one of the Hollywood screenwriters suspected of being a Communist or "fellow traveler" who was blacklisted from employment.

[11] To earn money, she gave drama lessons, managed to sell a couple of teleplays, and vied for various poorly paid film script assignments.