In mid-June 1945, one month after the end of the war, Erika Mann travelled for the last time in her capacity as a war correspondent to Europe. She remained until April 1946. Weimar, Paris, Luxembourg, Munich, Berlin, Prague, Vienna, Arosa were just some of the stops, as evidenced by her correspondence. Erika Mann wrote reports for the Press Department of the U.S. Army and wrote articles and reportage for the New York Liberty magazine and the London Evening Standard. In her articles, interviews, and letters she was shocked and disgusted by the apathy, the self-pity and the justifications of the Germans.

In August 1945 she visited Mondorf-les-Bains in Luxembourg where, strictly shielded from the public in a former hotel which had been converted into a prison, the "big 52" were interned, the former representatives of the Nazi regime. As a correspondent (and probably the only woman) she gained access e.g. to Hermann Göring, Alfred Rosenberg and Julius Streicher, about whom she wrote a major report for the Evening Standard.

From 20 November 1945 Erika Mann covered the Nuremberg war crime trials as an observer. Among the reporters were other emigrants such as Alfred Döblin, Peter de Mendelssohn and Alfred Kerr, plus international writers such as Ernest Hemingway, Louis Aragon, John Steinbeck, Martha Gellhorn and John Dos Passos.