Filmed in 1943 on the MGM lot in Culver City, CA, the film features an unusual assortment of non-Asian actors with odd accents playing Chinese and Japanese: Russian-born and Stanislavski-trained Akim Tamiroff as Wu Lien; Turhan Bey, Viennese born son of a Turkish father and Czechoslovakian mother as the middle son, Lao Er Tan; New England patrician Katharine Hepburn as his wife; American Aline MacMahon--no longer one of the wisecracking Gold Diggers of 1933 (1933)--as the wife of Ling Tang; English-born Henry Travers (best remembered as Clarence the Angel from It's a Wonderful Life (1946)) as the Third Cousin"; Irish-American J. Carrol Naish as the Japanese Kitchen Overseer; and finally Jewish Robert Lewis, co-founder of the Actors Studio and Meryl Streep's teacher at the Yale Drama School, as Japanese Capt. Sato.
On 21 October 1943, MGM was given permission to film exterior night scenes, not allowed since the wartime ban was instituted in 1941.
"March of the Volunteers" is sung by the resistance workers as they are resting on the Tan estate. The soundtrack has an orchestral version in several other scenes. It was in fact a popular song in China during the period portrayed. Since 1982, it has been officially recognized as the national anthem of the People's Republic of China.
Donna Reed was tested for the role of Orchid Tan, but even with make up did not look believable enough to be an Asian character.