Because of its unflattering portrait of the US military occupation staff in Italy, the film was not allowed to be shown in either the American or the British sectors of Germany.
Jerry is called "sergeant" by Giacomo and Pier Luigi, but the insignia he wears identifies him as a Technician Fifth Grade, or "Tech Corporal". This rank was created in 1942 for those with specialized skills (such as driving a truck, as Jerry does). Originally those who held it were addressed as "corporal", but the US Army revoked their non-commissioned officer status in November of 1943 to avoid confusion with those who had completed NCO leadership training. The rank was eliminated on August 1, 1948, less than two months before the film premiered.
Sister Gertrude (Enza Giovine) was based on a real person. She was a nun who cared for young women in the 5th Pavillion of Livorno Hospital.
John Kitzmiller, who plays Jerry Jackson, was a real-life member of the U.S. Army who fought in Italy in World War Two, and remained there after the war.