Audrey Hepburn turned down the title role in _Diary of Anne Frank, The (1959/I)_ to be in this film.
Heitor Villa-Lobos composed a large-scale score for the picture, but most of it was rejected by the studio. Bronislau Kaper was commissioned to write a new score, but insisted on incorporating some of the Villa-Lobos music. Villa-Lobos reworked his score as a concert suite, "Floresta do Amazonas (Forest of the Amazon)".
Pier Angeli was at one point considered for the role of Rima.
During the film, Rima is shown accompanied by a fawn. In order for the animal to properly bond with the actress, Audrey Hepburn effectively adopted the baby deer in the weeks preceding production.
In the 1970s, the character of Rima was revived for a comic book. In 1980 she was included in the Superfriends episode "Return of Atlantis".
This was the first major Hollywood film to be shot in Panavision. The Panavision process faced its first major test when Audrey Hepburn expressed worries that the widescreen process would distort her already square face. Test footage made in Panavision revealed this not to be the case, and reportedly received applause when it was shown for Hepburn and others in a test screening.