In a departure from most previous Tarzan films, "Greystoke" returned to Burroughs' original novel for many elements of its plot, updating the novel's story in the light of 1980s sensibilities and science. It also utilized a number of corrective ideas first put forth by science fiction author Philip José Farmer in his mock-biography "Tarzan Alive," most notably Farmer's explanation of how the speech-deprived ape man was later able to acquire language by showing Tarzan to be a natural mimic. According to Burroughs' original concept, the apes who raised Tarzan actually had a rudimentary vocal language, and this is portrayed in the film.
"Greystoke" rejected the common film portrayal of Tarzan as a simpleton that was established by Johnny Weissmuller's 1930s renditions, reasserting Burroughs' characterization of an articulate and intelligent human being, not unlike the so-called "new look" Tarzan films that Sy Weintraub produced in the 1960s.
The second half of the film, however, departs radically from Burroughs' original story. Tarzan is discovered and brought to Cumberland, where he fails to adapt to civilization. His return to the wild is portrayed as a matter of necessity rather than choice, and he is separated forever from Jane, who "could not have survived" in his world. Due to her heavy southern accent, Andie MacDowell (as Jane) had her voice dubbed by Glenn Close.
This is often called "the definitive version" of the Tarzan films.