The opening title card to the film reads "Paramount presents The Four Marx Brothers in Duck Soup." As noted by a May 1933 news item in MPH, the Marx Brothers left Paramount prior to making this film and filed suit against the studio over withheld profits. According to a modern source, the Marx Brothers planned to form a production company with Sam H. Harris. However, they resolved their differences with the studio and returned to fulfill their contractual agreement to make this fourth, and final, film for Paramount. According to information in the Paramount story files at the AMPAS Library, Grover Jones contributed to an early, temporary script entitled Cracked Ice, which Herman J. Mankiewicz was scheduled to supervise. A news item in HR indicates that M-G-M loaned Norman Krasna to Paramount to write an opening sequence for this film. His contribution to the final film has not been determined. Copyright records list Harpo Marx's character as "Brownie."
       Duck Soup was the last Marx Bros. film in which Zeppo Marx appeared. Modern sources note that Edward Kaufman and Keene Thompson were hired as writers, but left the production after a short time. Although modern critics cite this film as one of the Marx Brothers' best, and in 2007 the picture was ranked 60th on AFI's 2007 100 Years…100 Movies--10th Anniversary Edition list of the greatest American films (moving up from the 85th position it held on AFI's 1997 list), Duck Soup did not receive significant contemporary acclaim. Because box-office figures for the film were lower than anticipated, the brothers' Paramount contract was not renewed. Their next feature film was A Night at the Opera, produced by M-G-M (see below).