The film was the first starring Martin and Lewis to be shot in VistaVision. A clip from it was shown in a promotional short film, Paramount Presents VistaVision.
Pete Nelson, a smooth operator who has just been discharged from the Army, joins forces with his old buddy, the loud Jerome X. Hotchkiss, and together they join a circus. The Clyde Brent Circus, to be exact. Jerry has taken a job as apprentice lion tamer. He is set on being a circus clown, but his plans are squandered when they meet the circus manager Sam Morley and owner Jill Brent, who is also ringmaster. The circus has financial problems, so the only way that both Pete and Jerry can be hired if they help out wherever needed.
Jerry dutifully reports to the designated lion tamer, Colonel Schlitz, but is terrified when Schlitz forces him into the lions' cage with only a whip and chair for protection. Schlitz keeps calling at him to behave coolly and to show no fear, but all Jerry can do is to nervously try to befriend the beasts. Schlitz pulls him out of the cage.
Later in the day Jerry and Pete are washing the elephants when Jill stops by to chat. Pete starts flirting, which she finds both attractive and annoying. Jerry sneaks into Puffo the Wonder Clown's tent and tries on his hats. Morley catches him red-handed and scolds him.
One night while working in a custard stand. Pete and Jerry are overwhelmed by the crowd and lose control of the machine. Morley sends Jerry to help Puffo dress for his performance. The arrogant clown rejects Jerry’s help. Jerry's next assignment is to hand Nero, the tightrope walker, a unicycle. The audience roars with laughter at Jerry's fumbling attempts to climb a rope ladder while holding the bike. When Jerry accidentally ends up riding the unicycle on the tightrope, the crowd hushes. Pete and the clowns rush in with a net and catch him when he falls.
Saadia, the Queen of the Trapeze, is up to perform. She goes into the ring and Pete is indeed breath-taken by her great beauty. Jill, however, dislikes the egotistical, greedy Saadia. Morley insists the circus would go bankrupt without her. To Jill's disgust, Pete agrees to become Saadia's personal assistant.
Morley then talks Jerry into becoming a human cannonball. Pete, wearing nothing on his upper body, shows off for Saadia, giving her a private demonstration of his skills on the parallel bars. Saadia is attracted to Pete, and they end up kissing. They are interrupted by the slightly jealous Jill, who informs Saadia that, for financial reasons, there will be an extra show on Saturday.
Saadia is well aware of that the survival of the circus depends on her, but she refuses to do the extra show. Pete, watching her perform to a capacity crowd, gets an idea how to save the circus.
Morley finally allows Jerry to go into the ring in place of a sick clown. Jerry is ecstatic, but one performer unhappy with Jerry’s big break is Puffo. He resents the cheap laughs that Jerry gets from the audience and starts bullying him in the ring. The audience is upset and starts to boo Puffo, wanting him to go off. After the show Jerry tells Puffo that he is not angry with him.
Pete flirts with a very receptive Jill, but when he asks about the circus's profits, she is furious and slaps him. Soon after, in Saadia's tent, Pete explains to Jill his plan to increase the profits with gambling. A skeptical Jill, who inherited the circus from her father, allows Pete to set up some gaming tables on the midway.
The circus continues its tour. On Jill’s birthday, Pete and Jerry throw her a big party. Puffo gets quite drunk and interrupts the festivities to declare he is quitting. He will consider staying on if Jerry and Pete are fired. Pete gets angry and punches Puffo in frustration. Jill later dismisses Puffo from the circus and replaces his act with Jerry.
Jerry starts performing under the name Jerricho. He is an instant hit with the audience, even bigger than Saadia, who gets jealous. So jealous she too threatens to quit unless the circus gets rid of Jerry. Tired of her ego, Pete tells her "drive carefully" and sends her on her way. Jill is quite relieved that the alluring Saadia is out of her way.
However, her relief is short-lived. She witnesses a fight between Pete's shell-game operator and a customer, then demands that Pete stop the gambling operation. Pete refuses and announces he is leaving the circus, too. Sure that the loyal Jerry will go with him, Jill insists on leaving instead, preferring to leave the circus to Pete than lose it entirely.
Jerry verbally attacks Pete for canceling a benefit performance for disadvantaged children. Pete then tells Jerry he "ain't nice" anymore, and quits. Jerry and the other clowns decide to perform the show anyway, and Jill meets them at the outdoor arena.
Jerry’s words ring in Pete’s head while Jerry performs and delights the children with his clowning. Jerry goes to great lengths to get a sad-faced handicapped girl to laugh. A car arrives in the ring out of it comes Pete, dressed in a clown suit. Jerry and Jill are delighted to see Pete join in the fun.Dean Martin as Peter "Pete" Nelson
Jerry Lewis as Jerome F. "Jerry" Hotchkiss
Joanne Dru as Jill Brent
Zsa Zsa Gabor as Saadia
Wallace Ford as Sam Morley
Sig Ruman as Colonel Fritz Schlitz, Lion Tamer
Gene Sheldon as Puffo the Clown
Nick Cravat as Timmy
Elsa Lanchester as The Bearded Lady
An edited version was released by Paramount in 1978 entitled Jerrico The Wonder Clown and shown at children's matinees.
Due to a song rights issue, this film remains the only Martin and Lewis film without a home release.