The Italian crew was so upset over the assassination of Robert F. Kennedy, which occurred during the shoot, that they dedicated an extra hour of work in his memory. The letter from the Italian workers' union read, "the best way to honor the memory of a man of action is by action." Producer-director Stanley Kramer replied with the following announcement: "The decision of the Italian crew of The Secret of Santa Vittoria (1969) to dedicate one extra hour of work to the memory of Robert Kennedy has no parallel in motion-picture history. The American group in Anticoli Corrado is deeply honored to know you and privileged to be your coworkers."
During the fight scene, when Anna Magnani literally kicks Anthony Quinn out of the house, she kicked him so hard she broke her foot. Producer-director Stanley Kramer said of this in his autobiography "A Mad, Mad, Mad Mad World: A Life in Hollywood": "He and Magnani didn't get along at all. It's a wonder their scenes ever got finished. She didn't like him one bit, and in their big fight scene, when she was supposed to literally kick him out of the house, she did it so hard during the shooting that she broke her foot!" Kramer added: "She was a perfect lady. She greeted me in a formal gown, used a cigarette holder and spoke perfect English. She told me all about the studio there, where we would be doing some important interior sequences, and she described the business and artistic aspects of movie-making in Rome with a great deal of insight and intelligence and class. I thought wow, what a lady she is! And then she gave me a warning: 'Don't eat at the commissary here-the food is shit.' It was then I knew she had another side to her."
The real-life Italian town of Santa Vittoria could not be used for this movie because it had become too modernized since the Second World War period in which the film's story was set. A total of 169 Italian towns were location scouted until the right one was found: Anticoli Corrado. This is a municipality in the Province of Rome in the wider in region of Latium. The commune is situated about 40 km north-east of Rome.
The 500 Italian townsfolk of Anticoli Corrado who worked on this film donated a significant part of their earnings to finance the restoration of Renaissance frescos at Anticoli Corrado's Romanesque National Monument, the Church of San Pietro.
According to the film, the exact estimate number of bottles of wine that the township of Santa Vittoria had was 1,317,000. Publicity and word of mouth for the picture frequently approximated this down to one million bottles of wine. However, one of the film's main movie posters stated that there were actually 1,184,611 bottles of wine.