Homemaker Pat Kramer and her children, Beth and Jeff, return from the grocery store with bags of chemical-filled consumer products. As Pat and her maid, Concepcion, put away the groceries, next door neighbor, Judith Beasley, visits to demonstrate her latest cosmetic product line. Later, Pat’s husband, Vance Kramer, returns from a business trip and reveals that if his new products succeed, he could receive a partnership at work. Vance shows Pat a new perfume, and accidentally spills the liquid on her blouse. As she changes clothes, Pat suggests the perfume should be named “Sexpot.” While the couple makes love, the wet blouse sizzles. The next day, the blouse has disappeared and Pat telephones Vance to see if he took it to the cleaners, but he did not. Vance’s boss, Dan Beame, likes the “Sexpot” idea, and infers the promotion is available if Vance is equally successful with a new “Galaxy Glue” account. That evening, the Kramers host a neighborhood block meeting. When a guest breaks a vase, Vance tries the new glue, and it fixes the vase but also adheres to everything and everyone. The next morning at breakfast, Pat’s bracelet falls off her arm into Vance’s cereal, and they realize she has shrunk. Her doctor confirms that she is two inches shorter and still shrinking. He sends Pat to consult with Dr. Eugene Nortz and Dr. Ruth Ruth at the Kleinman Institute for the Study of Unexplained Phenomena. Their tests reveal Pat’s condition is caused by a mix of tap water, a flu shot, constant use of chemical products, and a unique imbalance in her system. Nortz and Ruth promise to find an antidote and send Pat home. As weeks pass, Pat continues to shrink. Her situation becomes a major news story, and she is reluctant to leave the house, but Judith Beasley convinces her to go grocery shopping. As Pat rides inside the cart, crowds gather. Pat wants to leave inconspicuously, but when Judith tries to sneak Pat out in a grocery bag, the manager stops her for shoplifting and is embarrassed to find the shrinking woman inside the sack. Pat attempts to live a normal life, but it becomes more difficult as she shrinks to doll size. Judith insists that Pat share the truth on television, and sets up an interview on the Mike Douglas talk show. Prior to the show, Vance confides to Dan that he fears Pat will disappear and wonders if the various products are dangerous. Dan counters that it is dangerous to destroy Americans’ faith in consumer products, and insists Pat must focus on the antidote, which Dan and Vance can advertise. During the interview, to Vance’s relief and Judith’s disappointment, Pat claims they do not know what causes her condition. Dan meets with Tom Keller and the members of Keller’s Organization for World Management as Dr. Nortz and Dr. Ruth reveal that a shrink serum could be developed from Pat’s blood. Keller learns that a few drops in a country’s water system would shrink masses of people, and he decides to shrink the rest of the world. At Christmas, Pat receives a dollhouse and moves into it to write her memoirs. Later, Pat is pushed by a mechanical robot into a closet, where she battles other mechanical toys and is soaked by a “Betsy Wetsy” doll. As Pat escapes the closet, Vance and Dan arrive with Keller, who poses as president of Paxton Toys. Dan and Keller want to market a Pat Kramer doll and insist she could make a fortune, but Pat refuses. As they leave, Keller and Dan plan another course of action. The next morning, Vance asks Pat to reconsider the offer because they need the money, but she is sick of products and advertising. Vance feels she is disparaging his work, and leaves. She climbs onto the window to stop him, but falls off the curtain and into the garbage disposal. Pat yells for Concepcion’s assistance, but the maid turns on loud music and does not hear Pat. Concepcion is about to turn on the disposal when the doorbell rings. As Keller’s henchman distracts Concepcion at the front door, someone else sneaks to the back door. Pat crawls out of the garbage disposal, but loses a sneaker in the sink as she is kidnapped. When Concepcion returns to the kitchen, she sees the sneaker, and assumes Pat died in the garbage disposal. Everyone mourns Pat’s death and they bury her shoe in a tiny grave. Meanwhile, Pat is locked in a hamster cage in a laboratory which also imprisons an ape named Sidney, who understands sign language and communicates his affection for Pat. Dr. Ruth arrives and questions the lab technician, Rob, about the monitors, and Rob blames Sidney for tampering with them. Pat learns that Keller, Nortz and Ruth are conspiring, and want Pat’s blood before she disappears. After Ruth leaves, Pat begs Rob to call Vance, but he refuses to get involved. As Rob wanders away, he knocks Pat’s file to the floor. Sidney retrieves the file for Pat, and she reads about Keller’s plan to shrink the rest of the world. When Rob returns, she shows him the evidence, and he agrees to help her. They telephone Vance, but while they talk, the line goes dead. As alarms blare, Pat insists Rob save himself. He promises to return, but Pat and Sidney hear gunfire in the hallway as guards arrive. By afternoon, Pat is too small to be contained by the hamster cage and is placed in a glass container. As Sidney tries to help her escape, Rob crawls inside the room. Though the guards believe he was killed, Rob hid until it was safe to return. Meanwhile, Vance announces on television that his wife is alive and has been kidnapped, but police do not believe him, and a representative from the Organization for World Management denies involvement, insisting Vance is crazy with grief. Keller decides they must kill Pat, but alarms go off again as Pat, Sidney, and Rob escape the laboratory, with the incriminating file. A chase ensues as the three escape through an elevator hatch, and emerge in a restaurant at the shopping center. Pat, Sidney, and Rob run outside, and see Judith outside the grocery store, carrying consumer awareness placards opposite a product demonstration table. Pat is shrinking fast, so Sidney places her on the table and Judith demands everyone listen, including a television reporter. Pat asks Rob to disseminate the evidence, and tells Sidney to take care of Rob. Vance and her children arrive, and Pat says she loves them. She claims to be part of everything and everyone, then shrinks again and disappears. As the crowd disperses, Pat’s tiny dress lands in a pile of spilled products and something bubbles. Later, as Judith leads a candlelight vigil outside the Kramer home, a police car arrives with Pat, who is now normal size. She landed on chemicals and swallowed something that made her grow again. Pat reunites with her family and Vance slides the wedding ring on her finger again, but it will not fit. Her finger is too big, and Pat smiles as her feet grow.