When she visited Obersalzberg on 13 June 1937 with 23 other students, she by chance had an encounter with Adolf Hitler, which she later called "one of the most intensive and strangest experiences in her life".

In 1947 she and her first husband Erich Peter Neumann founded a public opinion research organization—the Institut für Demoskopie Allensbach, which today is one of the best known and most prestigious polling organizations in Germany.

Noelle-Neumann was the president of the World Association for Public Opinion Research from 1978 to 1980 and worked as a guest professor at the University of Chicago from 1978 to 1991.

[7] In 1991, Leo Bogart criticized Noelle-Neumann, accusing her of anti-Semitic passages in her dissertation and articles she wrote for Nazi newspapers.

She declined, having fallen ill, which angered Goebbels; she later became a newspaper journalist with Nazi publications where she wrote some articles on Jewish influence over U.S. news and elite opinion.

Bogart's article appeared just weeks before Noelle-Neumann took up a visiting position in the Political Science Department at the University of Chicago, where she had held similar appointments since 1978.

Michael S. Kochin, then a graduate student at the university, noticed the article and circulated it on campus prior to her arrival,[9] igniting a vigorous debate on Noelle-Neumann's past.

[10] While the administration and students at the university,[11] the local Jewish defense groups,[12] and Chicago newspapers[13] remained disengaged from the issue, John J. Mearsheimer, then chairman of the university's political science department, spoke with Bogart, met for over three hours with Noelle-Neumann,[14] and called a departmental meeting about her on 16 October.

Moreover, I believe that the anti-Semitic writers and publicists of Germany – to include Noelle-Neumann – jointly share some responsibility for the Holocaust.

[20] Reached by telephone at her office in Allensbach am Bodensee, Germany, on 10 March, Noelle-Neumann told a reporter she was unaware of the proposed rally but intended on coming to the university as planned.

"[25] John Mearsheimer, Professor of Political Science at the University of Chicago wrote in The New York Times on 16 December 1991:"She has admitted she was not hostile to the Nazis before 1940.

[26][27] In an interview in the German newspaper Der Tagesspiegel, Noelle-Neumann said that while holding a scientific point of view, she also believed in angels and predestination.