- Nathan Lane - Max Bialystock
- Matthew Broderick - Leo Bloom
- Uma Thurman - Ulla
- Will Ferrell - Franz Liebkind
- Gary Beach - Roger De Bris
- Roger Bart - Carmen Ghia
- John Barrowman - Lead Tenor Stormtrooper
- Roland Rusinek - Jack Lapidus
- Jason Antoon - Jason Green
Following the flop of theatre musical "Funny Boy" (based on William Shakespeare's Hamlet), the show's washed-up producer, Max Bialystock, hires the neurotic Leo Bloom as his accountant. While studying Max's books, Leo notes that, since a flop is expected to lose money, the IRS won't investigate the finances of failed productions. Leo then jests that, by selling an excess of shares and embezzling the funds, a flop could generate up to $2 million. Deciding to enact the plan, Max asks for Leo's help with the scheme, only for the latter to refuse.
Returning to his old accounting firm, Leo soon starts fantasising about being a Broadway producer. Realizing that he wants to take the risk, Leo quits his job and forms "Bialystock & Bloom" with Max. Searching for the worst play written, the duo finds Springtime for Hitler, a musical written by an eccentric ex-Nazi named Franz Liebkind. Max and Leo, in order to acquire Liebkind's rights to the musical, perform Hitler's favorite song and swear the sacred "Siegfried Oath" to him.
In order to ensure the play's failure, Max and Leo meet failing, flamboyant director Roger De Bris and his assistant Carmen Ghia. De Bris is reluctant to direct, but when Max and Leo suggest he could win a Tony, he agrees on the condition that the play be more "gay". Returning to their office, a beautiful Swedish woman named Ulla, appears to audition. Despite Leo objecting they haven't started casting, Max insists on hiring her as their secretary until they audition her later.
To gain backers to fund the musical, Max has dalliances with several elderly women, allowing him to raise the $2 million. Finding himself attracted to Ulla, Leo laments about the dangers of sex straying him from his work, only for a kiss to occur between Leo and Ulla. Starting auditions for the role of Hitler, Franz becomes angered at a performer's rendition of a German song, causing Franz to storm the stage and perform it. Based on the performance, Max hires Franz to play Hitler.
On opening night, as the cast and crew prepare to go on stage, Leo wishes everyone "good luck," to which everyone warns it is "bad luck" to say "good luck" on opening night, and that the correct phrase is to say "break a leg". Franz leaves to prepare and, in his rush, literally breaks his leg. Max enlists Roger to perform the role in his place, and Roger accepts.
As the show opens, the audience is horrified at the first song, and people begin leaving out of disgust until Roger enters as Hitler. Roger, playing Hitler very flamboyantly, causes the audience to misinterpret the play as satire, resulting in the show becoming a surprise smash. Terrified the IRS will learn of their crimes, a dispute breaks out between Max and Leo. Franz then appears, and attempts to shoot the duo for breaking the "Siegfried Oath" by mocking Hitler, only to attract the police with gunshots. Max and Franz attempt to evade the police, only for Franz to break his other leg.
Arrested for his tax fraud, Max is imprisoned while Leo escapes by hiding from the police. Found by Ulla, Leo elopes with her to Rio de Janeiro, leaving Max to his fate. About to be sentenced in court, Max is saved by Leo, who returns to defend him. The judge, realizing Max and Leo are inseparable, sentences them both to five years at Sing Sing Prison with Franz. Writing and producing a new musical in prison, Leo, Max, and Franz are pardoned by the Governor for their work, allowing them to collaborate with Roger and Ulla and release "Prisoners of Love." The play's success means Max and Leo go on to become successful Broadway producers.
In a post-credits scene, the cast appears, telling the audience to leave the theater. Mel Brooks appears at the end of the song and says, "It's over."
The songs "The King of Broadway", "In Old Bavaria" and "That Face (reprise)" were cut from the final film.
- Act I
- "Opening Night" – Usherettes and First-Nighters
- "The King of Broadway" – Max and Street People
- "We Can Do It" – Max and Leo
- "I Wanna Be a Producer" – Leo, Showgirls, and Accountants
- "We Can Do It" (Reprise) – Leo and Max
- "I Wanna Be a Producer" (Reprise) – Leo and Max
- "In Old Bavaria" – Franz
- "Der Guten Tag Hop-Clop" – Franz, Leo and Max
- "Keep It Gay" – Roger, Carmen, Max, Leo, Production Team, and Roger's Housemates
- "When You've Got It, Flaunt It" – Ulla
- "Along Came Bialy" – Max and Company
- Act II
- "That Face" – Leo and Ulla
- "That Face" (reprise) - Max
- "A Wandering Minstrel I" - Jack Lapidus
- "Haben Sie gehört das deutsche Band?" - Jason Green
- "Haben Sie gehört das deutsche Band?" (reprise) – Franz
- "You Never Say 'Good Luck' on Opening Night" – Roger, Carmen, Franz, Leo, and Max
- "Springtime for Hitler" (part 1) – Lead Tenor Stormtrooper, Bavarian Peasants, Tapping Brown-Shirts, Showgirls, Ulla, and Company
- "Heil Myself" – Roger
- "Springtime for Hitler" (part 2) – Roger, Ulla, and Company
- "You'll Find Your Happiness in Rio" - Waiters
- "Betrayed" – Max
- "Till Him" – Leo, Max, and Little Old Ladies
- "Prisoners of Love" – Roger, Ulla, and Company
- "Leo and Max" – Max, Leo, and Chorus
- "There's Nothing Like a Show on Broadway" - Leo and Max
- "The Hop Clop Goes On" - Franz
- "Goodbye!" – All