The film was originally intended to be an independent production. Then Disney became involved and provided additional financing, increasing its budget from $18 million to nearly $30 million in the process.
Filming in Monkey City proved to be quite difficult. It was already extremely hot in India (where the scenes were filmed) and the flame ledges used toward the end of the film, routinely caused the ambient temperature to reach 137 degrees Fahrenheit.
The only animal that is not actually a real one is Kaa. Due to the difficulty in training snakes, a combination of CGI, animatronics and puppetry was used. Also in this film adaptation he is not referred to by his name; only once he is referred to as "The Great Snake" by Mowgli.
During the social gathering at the British palace, Dr. Plumford (John Cleese) comments on the presence of both Indian and English cultures present by saying the party had "all the bare necessities of life"; a nod to the famous song "Bare Necessities" sung by Baloo from the original film The Jungle Book (1967). Later in that same scene, there's a subtler reference to "I Wanna Be Like You" when Wilkins (Jason Flemyng) says "But perhaps he can teach us how the apes dance."
Unlike versions before or since, this is the only time where Shere Khan is not a villain but rather a neutral force of nature. Stephen Sommers stated it would be impossible for him to allow Shere Khan to be killed for his actions seeing how majestic tigers are.
One of few films that have the principle animal actors' names in the credits. These animal actors were Casey (the main bear who played Baloo), Shadow (the main panther who played Bagheera), Shannon (the wolf who played Grey Brother), Lowell (the orangutan who played King Louie), and Bombay (that main tiger who played Shere Khan).
All the scenes featuring King Louie, Lowell, the orangutan playing King Louie, was shot on a soundstage in LA against blue screen due to certain restrictions with primates that didn't allowed the production to bring him on location in India. According to Stephen Sommers, he was the easiest animal to work with and the most entertaining. Lowell loved the attention he was getting from the crew so he started to urinate all over the blue screen which caused the whole crew to burst into laughter. Lowell then started to swat his urine everywhere which caused the laughter to grow louder. His crowning achievement was beginning to suck on his fingers, the laughter continued to grow louder.
The trivia items below may give away important plot points.
Actor Jason Flemyng was not present for the scene when Wilkins is chased down by Shere Khan and killed. Instead stunt personnel who were experienced in working with animals, particularly with tigers, were involved. The stunt man and the tiger were both trained in a play behavior that gave the appearance of the tiger mauling Wilkins.
Director Stephen Sommers said that the most difficult scene to film was the one in which Mowgli runs back to seek Dr. Plumford's help after Baloo is shot. For the scene a camera was mounted on an ATV and Jason Scott Lee had to run alongside it, careful to remain in frame as well as possible.