In 1958, she became the youngest member of the Josefstadt Theatre in Vienna and appeared in productions of L'Œuf, Charley's Aunt, Much Ado About Nothing' and Cat on a Hot Tin Roof.

[4] In 1960, Bernhard Wicki and Artur Brauner produced the comedy film The Good Soldier Schweik with Berger and German actor Heinz Rühmann.

In 1962, she went to Hollywood and worked with stars such as Charlton Heston, Dean Martin, Frank Sinatra, Richard Widmark, John Wayne, Kirk Douglas, and Yul Brynner.

Also in 1965, she starred in The Glory Guys, a dramatic representation of Custer's Little Big Horn disaster, based on the novel The Dice of God by Hoffman Birney.

In The Quiller Memorandum, a third film of hers released in 1966, she played opposite Max von Sydow and George Segal in the role of a German schoolteacher involved in neo-Nazi activity.

Other internationally successful films made by their joint production company included, Die weiße Rose (1982), The Nasty Girl (1990) and My Mother's Courage [de] (1995).

She also acted alongside Schell and James Coburn in a supporting role in the acclaimed war film Cross of Iron (1977).

(In the 1980s, Berger discovered she was admired by Scottish drifter Arthur Richard Jackson, who had attempted to murder American actress Theresa Saldana in 1982.)

From 2003 to 2010, Berger was president of the German Film Academy, which seeks to support the careers of actors and actresses in Germany and across Europe.

In 2005 she appeared in the film, Einmal so wie ich will (Once According to My Will), as a woman trapped in an unhappy marriage, who finds love on holiday, but turns her back on the relationship.

[9] In June 2023, her romantic dramedy Remember Me [de] (Weißt du noch; screenplay by Martin Rauhaus, directed by Rainer Kaufmann) premiered at the 40th Filmfest München.