Leo McCarey put his directorial spoon into Duck Soup because he had impressed the Marx Brothers with his direction of their fellow vaudevillian Eddie Cantor's musical The Kid from Spain (1932). As flattering as their approval might have been, McCarey did not warm up to the project, as he told Cahiers du cinema in 1967:

"I don't like (Duck Soup) so much...I never chose to shoot this film. The Marx Brothers absolutely wanted me to direct them in a film. I refused. Then they got angry with the studio, broke their contract and left. Believing myself secure, I accepted the renewal of my own contract with the studio. Soon, the Marx Brothers were reconciled with (Paramount)...and I found myself in the process of directing the Marx Brothers. The most surprising thing about this film was that I succeeded in not going crazy, for I really did not want to work with them: they were completely mad."

Screenwriters Harry Ruby and Bert Kalmer were standing on the set of one day when an extra standing next to them said, "I don't know who wrote this stuff but they ought to be arrested...they should be in a different business." Kalmer, who was known as a rational and calm man, said to Ruby, "I'm going over to hit him. Who does he think he is? He's just an extra!" But before fisticuffs erupted, Kalmer and Ruby were informed that Chico Marx had paid the extra to rib the screenwriters, just for the hell of it.

Some screenwriters did not survive the Marx Brothers long enough to be ribbed at all. Two Paramount contract writers, Grover Jones and Kean Thompson, were both eager and willing to be assigned to Duck Soup. They were each hired at different intervals, but both had disappeared from the production after two weeks' work. They simply did not have the stamina and perseverance in dealing with the Marx Brothers.

As far as Groucho Marx was concerned, Margaret Dumont, playing the matronly Mrs. Teasdale, was practically the fifth Marx Brother. She always played her scenes with Groucho and the boys in Duck Soup and their other pictures as if they were the most serious and dignified scenes ever put to film. Her ramrod straight and sincere acting make the picture's madcap humor and satire that much more effective. Just look in the final scene: Dumont truly sings her heart out as the Brothers pound her mercilessly with custard pies. Groucho later said of her, "She was a wonderful woman. She was the same offstage as she was on it - always the stuffy, dignified matron. She took everything seriously. She would say to me, 'Julie, why are they laughing?'" Apparently, Dumont truly did not get most of the Marx Brothers' brand of humor.

To help sell Duck Soup to theater exhibitors and the public, the Paramount press department featured a number of contests to get the word out about the newest Marx Brothers laughfest. In addition to "Name the Four Marx Sisters," there was also a proposed duck-hunting contest, in which hunters across the fruited plain would bring back their catch to be cooked in one big duck dinner, beginning with duck soup, of course. And then there was the duck parade. Just imagine, to paraphrase the Paramount press materials, after you round up four ducks (preferably from a poultry market or a farmer), dress them as the Brothers, and let them lead the parade, you, the faithful theater manager, could then create more nonstop hilarity by tying the ducks together with a long string. "The ducks will not stay in line but that will only add to the confusion and the excitement," the press materials helpfully added.

In the original script, there was to be a romance between Raquel Torres and Zeppo Marx, but it was cut before the picture's release. In fact, after the premiere of Duck Soup, Zeppo cut himself from the comedy team altogether, citing a dissatisfaction with movie acting overall, and a weariness with being the butt of jokes regarding him as the "unfunny" Marx brother. But contrary to the commonly accepted story, Zeppo did not leave to represent his brothers as their showbiz agent. In fact, the only deal Zeppo ever spearheaded for his brothers was with RKO Pictures, for the 1938 movie, Room Service. Upon making his exit from the cameras, Zeppo, and another Marx brother, Gummo eventually represented a number of talented writers and actors, including George S. Kaufman, Dorothy Parker, Lucille Ball, Fred MacMurray, Barbara Stanwyck, Jean Harlow, and Lana Turner. It was Gummo, not Zeppo, who became the Marx Brothers' formal agent.

Shortly before Duck Soup premiered in November 1933, the city of Fredonia, New York, complained about the use of its name with a missive from the town mayor that read, "The name of Fredonia has been without blot since 1817. I feel it is my duty as mayor to question your intentions in using the name of our city in your picture." Groucho replied in writing, "Your Excellency: Our advice is that you change the name of your town. It is hurting our picture. Anyhow, what makes you think you're Mayor of Fredonia? Do you wear a black moustache, play a harp, speak with an Italian accent, or chase girls like Harpo? We are certain you do not. Therefore, we must be Mayor of Fredonia, not you. The old gray Mayor ain't what he used to be."

Another "state" objected to Duck Soup in a big way. Benito Mussolini, the fascist Italian dictator, took the film's parodic assault on war and dictatorships quite personally, so he banned the film in Italy completely. Naturally, the Marx Brothers were quite happy to hear that their film was being received so vociferously in fascist Europe. All their films were already banned in Germany, not because of their satirical jabs against fascism, but because the Marxes were Jewish.

Irving Thalberg, the production chief at MGM, felt that the Brothers' Paramount films were lackluster box office performers because their characters were mostly "unsympathetic." He felt that if the characters were motivated by helping the two romantic leads of the picture, then audiences would be more pleased overall. The failure of Duck Soup at the box office gave some credence to Thalberg's argument. Indeed, the Marxes' biggest moneymakers, A Night at the Opera (1935) and A Day at the Races (1937), were made under Thalberg's supervision and with the understanding that the boys were not to be uninhibited anarchists, but rather Cupid's helpers. On the other hand, Duck Soup features no sappy romantic interludes that you would want to fast forward through, something that mars the MGM pictures.

Duck Soup will probably leave you with one question: what's with that title? While their Paramount films all had enigmatic titles, such as Horse Feathers (1932), the Duck Soup title actually had an explanation behind it. Groucho explained: "Take two turkeys, one goose, four cabbages, but no duck, and mix them together. After one taste, you'll duck soup the rest of your life."