Private investigator Tom Welles (Nicolas Cage) is contacted by Daniel Longdale (Anthony Heald), attorney for wealthy widow Mrs. Christian (Myra Carter), whose husband has recently died. While clearing out her late husband's safe, she and Longdale found an 8mm film which appears to depict a real murder of a girl, but Mrs. Christian wants to know for certain.
Growing up, Evan Treborn, and his friends, siblings Kayleigh and Tommy Miller, and Lenny, suffered many severe psychological traumas that frequently caused him to black out. These traumas include being coerced to take part in child pornography by Kayleigh and Tommy's father, George Miller (Eric Stoltz), being nearly strangled to death by his institutionalized father, Jason Treborn (Callum Keith Rennie), who is then killed in front of him by guards; accidentally killing a mother and her infant daughter while playing with dynamite with his friends; and seeing his dog being burned alive by Tommy.
Seymour "Sy" Parrish (Robin Williams) is a photo technician at SavMart's one-hour photo developing clinic. He leads a solitary life outside of the "heaven-like" hyperreality atmosphere of the department store. Every day he labors to ensure his customers get the best quality photos possible. His work is his life, as he has no one and nothing to go home to at the end of each day; he spends his evenings sitting alone in his barren living room, watching television. The only thing in Sy's apartment he has for companionship is a hamster, caged in his bedroom. His favorite customers are the Yorkin family: husband Will (Michael Vartan), wife Nina (Connie Nielsen), and their son Jake (Dylan Smith). He has developed their photos for years and has developed an obsession with the family. He idolizes their happiness and affluence, memorizing every personal detail about them, and begins to associate with them more and more hoping to become a part of their lives.
In 1991 Los Angeles, slacker Jeff "the Dude" Lebowski (Jeff Bridges) is assaulted in his home by two thugs (Mark Pellegrino and Philip Moon) who demand money that the wife of a Jeffrey Lebowski owes to a man named Jackie Treehorn (Ben Gazzara). The two soon realize they have attacked the wrong Jeffrey Lebowski and leave, but not before one of them urinates on The Dude's rug.
In 1977, Eddie Adams is a high school dropout who lives with his stepfather and emotionally abusive alcoholic mother in Torrance, California. He works at a Reseda nightclub owned by Maurice Rodriguez, where he is discovered by porn director Jack Horner, who auditions him by watching him have sex with Rollergirl, a porn starlet who always wears skates. After a heated argument with his mother about his girlfriend and sex life, Adams moves in with Horner at his San Fernando Valley home.
Zack Brown and Miri Linky are roommates in Monroeville, Pennsylvania (a Pittsburgh suburb). They have been friends since the first grade. Despite Miri working at the local shopping mall and Zack working at a coffee shop, they have not paid their utility bills in months, with Zack devoting much of his free time to a fanatic following of the Pittsburgh Penguins and his status in the community amateur hockey team, the Monroeville Zombies. After work, their water gets turned off before they go to their high school reunion.
Ambitious high school senior Matthew Kidman (Emile Hirsch) has been accepted to Georgetown University, but cannot afford the tuition. He has raised $25,000 in order to bring a brilliant Cambodian student, Samnang, to study in the United States, but finds little else truly memorable about his high school experience. His life suddenly changes when charismatic Danielle (Elisha Cuthbert) moves in next door. Matthew witnesses her undressing from his bedroom window, until she sees him and storms over, knocking on the door and introducing herself to his parents. They suggest to Matthew that he show Danielle around town.
Jon Martello is a modern day Don Juan, with a short list of things he cares about: "my body, my pad, my ride, my family, my church, my boys, my girls, my porn". Though he has a very active sex life, he is more sexually satisfied by viewing pornography and masturbating, which enables him to "lose himself".
Ramu Gupta (Jimi Mistry), a dance teacher, leaves his native city Delhi, India, to seek his fortune in the United States. He is lured by the exaggerations of his cousin, Vijay, who has already moved to New York City. Vijay's deception is the first of several that drive the plot.
In 1952, 10-year-old Larry Flynt is selling moonshine in Kentucky. Twenty years later, Flynt and his younger brother, Jimmy, run the Hustler Go-Go club in Cincinnati. With profits down, Flynt decides to publish a newsletter for the club, the first Hustler magazine, with nude pictures of women working at the club. The newsletter soon becomes a full-fledged magazine, but sales are weak. After Hustler publishes nude pictures of former first lady Jackie Kennedy Onassis, sales take off.
Jake Scully (Craig Wasson) is a struggling actor who has lost his role as a vampire in a low-budget horror movie after his claustrophobia thwarts shooting. He returns home to discover his girlfriend cheating on him, so Scully is left without a place to stay.
Harry Mitchell (Roy Scheider) is a successful industrialist living in the suburbs of Los Angeles whose wife Barbara (Ann-Margret) is running for city council while he is having an affair. Harry is confronted by three blackmailers demanding $105,000 for a videotape of him and his mistress, Cini (Kelly Preston).
Germain Dagenais, a former solicitor (Côté), discovers evidence from a crime scene which included a dead body, of a videotape that included pornography. He is interested in viewing porn during his private time and accidentally finds his own daughter Nathalie (Karine Vanasse) in a video announcing she will be in a future video. Panicked, Germain must find his daughter and save her before she meets the same fate.
A small-town manchild with big buck-teeth, Bucky Larson (Nick Swardson), stumbles upon a family secret: His quiet and reserved parents (Edward Herrmann and Miriam Flynn) were famous porn stars in the 1970s. This motivates him to leave northern Iowa for Hollywood, hoping to follow in their footsteps and fulfill his destiny as the biggest adult-film star in the world. Unfortunately, he has no idea how to become a porn star like his parents, and his penis is incredibly small.