Goldie Hawn did most of her own stunts, after being convinced by Mel Gibson to do so. She was originally reluctant to perform them, fearing the harsh and overwhelming nature of the tasks. She was eventually so pleased with her stunt performances that she kept her stuntman's jacket after filming resumed, and as of 2017 still exhibits it next to her Oscar statuette.
The baboon was, according to the film's production notes on the DVD, the only male baboon in the world that was trained to work in front of a camera.
Two watering crews were employed to water all the plants in the rainforest on a full-time basis, right throughout the zoo shoot.
Originally this film was supposed to star Kurt Russell opposite his real-life partner Goldie Hawn. However, Russell had already committed to star alongside Sylvester Stallone in Tango & Cash (1989), which was filming at the same time but released several months before this. Russell suggested that director John Badham ask his Tequila Sunrise (1988) co-star Mel Gibson if he would be interested and Badham was pleasantly surprised when Gibson accepted.
The final negotiating point to convince Mel Gibson to do this film was the offer of a use of a producer's house for the summer, allowing him to shoot the film and give his large family an excellent summer vacation home.