In New York City, a cardboard box with a litter of kittens is placed on the sidewalk, advertising that they need a home. As people adopt them, the last one left is an orange kitten named Oliver. During a rainstorm, the box breaks apart and Oliver flees for shelter. In the morning, Oliver is hungry and wanders to a hot dog stand. However, Louie, the vendor, yells at him to leave. As Oliver turns away, Dodger, a streetwise dog, approaches. Instructing Oliver to distract Louie, Dodger steals sausage links, but refuses to share with the kitten. Feeling cheated, Oliver follows Dodger to a barge tied up beneath the docks. Sneaking inside, Oliver sees Dodger share the sausages with four other dogs: Tito the Chihuahua; Francis the Bulldog; Einstein the Great Dane; and Rita the Saluki. As the dogs eat, Fagin, the barge’s owner and a pickpocket, arrives home worried that he does not have enough money to repay a loan from Sykes, owner of Sykes Shipping and a loan shark. Suddenly, Roscoe and Desoto, Sykes’ two Doberman Pinschers, burst onto the barge. As Fagin goes to speak to Sykes on the dock, Desoto finds Oliver hiding. Scared, Oliver scratches Desoto’s nose. Desoto and Roscoe chase him, but Dodger recognizes Oliver and orders them to leave him alone. Meanwhile, Fagin tells Sykes he does not have the money. Upset, Sykes threatens Fagin to pay him back in three days. Returning to the barge, Fagin asks the dogs who scratched Desoto’s nose. When they show him Oliver, Fagin invites the kitten to be a part of their crew. The following day, Fagin drives the dogs and Oliver into the city on his scooter with an attached basket, and instructs the animals to find the money to pay Sykes. Seeing a limousine, Dodger plans to steal the car stereo. As Dodger instructs how to stop the car, Jenny Foxworth, a lonely little girl, reads a letter aloud to the family butler and chauffeur, Winston, that her parents will not return home from Europe in time for her birthday. At Dodger’s signal, Einstein and Francis create a distraction to get Winston out of the limousine. When Tito and Oliver try to remove the stereo, Jenny startles them. The wires shock Tito, throwing him out of the vehicle. Seeing Oliver, Jenny offers to take him to her home as her new pet. Arriving at her family’s Fifth Avenue townhouse, Jenny shows Oliver around as Winston awakens the Foxworths’ champion show dog, Georgette. When Jenny informs Georgette that Oliver will be living with them, the Poodle becomes jealous. Meanwhile, Dodger believes Oliver is in trouble for the failed heist, and makes a plan to rescue him. After Jenny leaves for school, Dodger, Tito, Francis, Einstein and Rita break into the house and run into Georgette. When Dodger explains they came for Oliver, Georgette happily leads the dogs to where the kitten is napping. Seeing Oliver with a new collar, Rita suggests he stay with Jenny. However, Georgette insists he should leave immediately. Placing Oliver inside a pillowcase, the dogs return to Fagin’s barge. After awakening, Oliver tells them he was happy in his new home. Insulted that Oliver thinks the crew is too lowbred, Dodger tells him to leave. Fagin returns and sees Oliver’s collar with a tag listing Jenny’s Fifth Avenue address. Seeing his chance to pay back Sykes, Fagin writes a ransom note demanding money for Oliver’s return. After telling Sykes he will have his money after collecting the ransom, Fagin, Oliver and the dogs go to the docks. Jenny arrives with Georgette and her piggy bank. Fagin feels guilty and pretends to “find” Oliver for Jenny. Suddenly, Sykes drives up and kidnaps Jenny for his own ransom plan. Following Sykes to his warehouse, Oliver and the dogs sneak inside to find Jenny guarded by Desoto and Roscoe. Creating distractions, Oliver, Dodger, and the others free Jenny and escape with Fagin on his scooter. Fagin drives onto subway tracks leading to a bridge over the river, but Sykes and his dogs follow. Sykes grabs Jenny and Oliver bites his hand, while Dodger fights off Desoto and Roscoe. With a train coming toward them, Jenny jumps into Fagin’s arms and Tito steers the scooter onto a bridge suspension cable. Before the train hits Sykes’s car, Oliver and Dodger jump to safety. Later, Jenny celebrates her birthday with her pets, Oliver and Georgette, and her new friends, Dodger, Francis, Einstein, Rita, Tito and Fagin. Afterward, Fagin and the dogs say goodbye, but Dodger tells Oliver that he will always be a part of their crew.