The film was screened at weekend matinees during its original U.S. release, and made over US$6.5 million. It was not a critical success; reviewers found fault with the story and animation style. The film was released on VHS in late 1985, and on DVD in early 2004. Another Littles film, Liberty and the Littles, premiered on television in late 1986.
Henry Bigg learns that his parents have been lost during an archaeological trip to Africa, although the remains of their plane have been found. His housekeeper Mrs. Evans says his Uncle Augustus is his next of kin and therefore his legal guardian. Thus, Henry moves to Augustus' residence, as the uncle neither wants to have a housekeeper nor move to his nephew's house.
Meanwhile, Tom and Lucy Little (two of the tiny people inside the walls of Henry's house) snag an apple that Mrs. Evans had left for Henry. They repay the boy by finding his lucky rabbit's foot and sneaking it in his suitcase. They are carried away to Augustus' house, trapped inside the luggage. Another two of the tiny creatures, Grandpa and Dinky, soon find them.
There, the Littles soon learn of Augustus' ill-tempered and mean-spirited ways: He treats Henry more like a slave, and is planning on replacing his nephew's house with a shopping mall. While the creatures try to escape, Henry discovers Grandpa and Dinky, not knowing who—or what—they are. Augustus also sees them, but mistaking them for toys, grabs them from Henry and locks them in the desk drawer in his study. Here, Dinky and Grandpa discover that Augustus forged the documents in order to become Henry's legal guardian, as well as to steal and redevelop the Biggs' property.
To rescue those two, Lucy persuades Tom to talk to Henry—a bold move, considering that humans never knew about the creatures until recently. Grandpa and Dinky, whom Henry finds inside the study, both prove the evidence of Augustus' fraud. Before Augustus locks him inside his room, Henry soon creates a diversion allowing Tom and Lucy to save them.
Eventually, Lucy and Tom are hungry, and begin to search for food. Tom gets trapped in a jar of honey, and a change of plans ensues: the Littles must rescue Henry before they can save Tom. At first Grandpa resists, but consents since Henry has already met them.
After several attempts to escape, the Littles finally flee away aboard their gas-powered toy plane, but cause a garage fire that wakes up Augustus. Henry attempts to go to the police station, but gets lost and is eventually caught by his uncle. The Littles, however, distract Augustus long enough for Henry to run down there. Meanwhile, Augustus orders the demolition crew by phone to start tearing down the Biggs' place.
When the Littles get to Henry's house, they split up; Grandpa looks for Mr. and Mrs. Little while the others try to sabotage the bulldozer. Both plans succeed just in the nick of time. The moment Augustus arrives, policemen arrest him.
Henry is reunited with Mrs. Evans, and prepares to meet his rediscovered parents at the airport. He casts a knowing wink at the gate, as the Littles watch on.
Along with The Smurfs and the Magic Flute and The Secret of the Sword, Here Come the Littles was among the first animated films handled by U.S. distributor Atlantic Releasing. The film was based on the ABC TV series of the same name, and produced in France by DIC Entertainment in conjunction with ABC.
The film was released theatrically in early 1985, and was released on the VHS format in late 1985 by CBS/Fox's Playhouse Video label, under license from ABC Video Enterprises. It was released on DVD by UAV Corporation on February 24, 2004, and re-issued by NCircle Entertainment on August 21, 2007.
In 1984, Scholastic Books published a 64-page tie-in adaptation by Lorentz Carlson (ISBN 0-590-33149-3).
During its run in the North American market, Here Come the Littles grossed over US$6.5 million through weekend matinee showings.
The film was not well-received with critics. It received generally mixed reviews. Candice Russell of the South Florida Sun-Sentinel wrote: "[It] has all the panache of a Saturday morning cartoon and just about as much heart. It's even in the same mode of repetitive crises every third minute."
The Los Angeles Times' Charles Solomon said, "[It] boasts an international pedigree more complicated—and interesting—than its storyline." In his Movie Guide, Leonard Maltin gave it 1½ stars out of four and called it a "silly, boring animated effort". Likewise, the Blockbuster Entertainment Guide to Videos and Movies gave it two stars, and recommended it "for fans of the Littles book series only". Jerry Beck, in his Animated Movie Guide, gave it only one star and commented: "The film raises issues of homelessness, the loss of parents, and the importance of family and friends, in a mild, one-dimensional way." Along with Russell, he criticized the "bland style" of the animation, which was outsourced in Japan.
A review in the San Francisco Chronicle stated that Here Come the Littles "is an OK, though hardly memorable, entertainment for small children. Come to think of it, pity the runts of today who get nothing but mediocre big screen fare—when they get it at all".
A made-for-television follow-up, Liberty and the Littles, aired on the ABC network in 1986 as part of its Weekend Special anthology series. It first aired in three parts of 30 minutes, on October 18, October 25, and November 1. In the film, the Littles fly to the Statue of Liberty, and come across a group of French relatives who are under a tyrant's control.
According to one crew member, Liberty was planned for a theatrical release, but ended up on television because of a change in management during production.