A bachelor author of sleazy books moves to a family-oriented subdivision where he becomes an unofficial relationship advisor to unhappy local housewives, to the dismay of their respective husbands who suspect him of sexual misconduct.
Former radio singer Kay learns from her gossipy friends that her husband, Steve, has had an affair with chorus girl Crystal. Devastated, Kay tries to ignore the information, but when Crystal performs one of her musical numbers at a charity benefit, she breaks down and goes to Reno to file for divorce. However, when she hears that gold-digging Crystal is making Steve unhappy, Kay resolves to get her husband back. The Opposite Sex is a remake of the 1939 comedy The Women.
On an airliner bound for Hong Kong, Tony, a career crook who deals in stolen diamonds, agonizes over whether he should stick with his girlfriend or pursue Pamela, an intriguing novelist with whom he's instantly infatuated. Viewing Tony's dastardly deeds as great material for her new book, Pamela gladly encourages him to continue his criminal behavior.
Jobless sportswriter Eddie Willis is hired by corrupt fight promoter Nick Benko to promote his current protégé, an unknown Argentinian boxer named Toro Moreno. Although Moreno is a hulking giant, his chances for success are hampered by a powder-puff punch and a glass jaw. Exploiting Willis' reputation for integrity and standing in the boxing community, Benko arranges a series of fixed fights that propel the unsophisticated Moreno to #1 contender for the championship. The reigning champ, the sadistic Buddy Brannen, harbors resentment at the publicity Toro has been receiving and vows to viciously punish him in the ring. Eddie must now decide whether or not to tell the naive Toro the truth.
An electric shock enables Satch to predict numbers, so the Bowery Boys are off to Las Vegas to win enough money at the roulette wheels to let their landlady buy an apartment building. Witnessing his winning streak, some gangsters decide to move in and find out his "system" for beating the odds.
Composer Gary Stuart (Ray Milland) and his wife, Connie (Jane Wyman), have an argument over her alleged affair with Courtney Craig (Tom Helmore). The Stuarts agree to get divorced, and each tries to move on to a new love: Gary with socialite Deborah Randolph (Karin Booth) and Connie with businessman Frank McGraw (Aldo Ray). However, they start to realize that they still have strong feelings for each other. The Stuarts must make a decision before their divorce is final.