Although he normally did not enjoy films which show children or infants in danger, Gene Siskel gave this movie a "thumbs up" while Roger Ebert disliked the movie, and told Siskel he should be ashamed of himself. Their sharp disagreement has since become a popular Internet video.
In a 2009 essay, published after the death of John Hughes, Roger Ebert included this tidbit about a trip to India: "Once when I was visiting the largest movie theater in Calcutta, I asked if 'Star Wars' had been their most successful American film. No, I was told, it was 'Baby's Day Out,' a Hughes comedy about a baby wandering through a big city, which played for more than a year." An Indian remake, Sisindri (1995) was released the following year.
This was the first film of John Hughes' three picture fifty million dollar contract with Fox, which produced Baby Day's Out, Miracle On 34th Street (1994), and Home Alone 3 (1997), all of which were box-office failures.
The majority of the film was shot on soundstages at 20th Century Fox Studios, especially for the major shots in the film, such as the Cotwell mansion (which was redressed several times for other shots), the Chicago Zoo and the construction site, the film's major set piece.
Originally, Academy Award Winning Composer Jerry Goldsmith was slated to score this film, but had to bow out, due to scheduling conflicts with The Shadow (1994). Bruce Broughton was hired, and subsequently hired to score the remake of Miracle on 34th Street (1994) later that year, both written and produced by the late John Hughes. Broughton had only three weeks to score the film.
At one point in the film, Laraine Cotwell (Lara Flynn Boyle) tells F.B.I. Agent Grissom (Fred Dalton Thompson) that he can't possibly know how she feels, since he has never lost a child. Also, Eddie (Joe Mantegna) says that he'll never have any kids of his own. In reality, however, both Thompson and Mantegna are fathers, while Boyle has no children.
The gorilla suit used in this film was the same suit John Alexander wore to play Digit in Gorillas in the Mist. Both films had Rick Baker creating the animatronic effects, and he made alterations to the suit for this film since the character is supposed to be a western lowland gorilla as opposed to being a mountain gorilla.
When trying to act natural and not be noticed by construction crews going down the elevator, Veeko (Brian Haley) goes to the 'position of attention', a facing movement among all US military branches. Brian Haley served in the Army.