Zaentz's film production career, primarily financed by the profits from Creedence Clearwater Revival, was marked by a dedication to the adaptation of novels.

After serving in the U.S. Army during World War II, Zaentz began realizing his passion for music by working for Jazz at the Philharmonic and record company head Norman Granz, a job that included managing concert tours for musicians such as Duke Ellington and Stan Getz.

The partners signed roots-rock group Creedence Clearwater Revival (CCR),[7] fronted by former Fantasy warehouseman John Fogerty.

Songs about the experience on Fogerty's 1985 album Centerfield – "Zanz Kant Danz" and "Mr. Greed" – were thinly veiled slams at Zaentz.

Zaentz also unsuccessfully sued Fogerty for plagiarism, claiming that the melodic line in "The Old Man Down the Road" (on Centerfield) was a lift from the Fantasy-copyrighted-but-Fogerty-written song "Run Through the Jungle" from CCR's 1970 album Cosmo's Factory.

[11] Fogerty continued to maintain that the label misled him about investing and managing his earnings from royalties, resulting in devastating financial loss.

It won eight Academy Awards, including Zaentz's second Best Picture, and spun off a best-selling soundtrack album (distributed by Fantasy Records).

Zaentz next produced The Mosquito Coast, directed by Peter Weir on location in Belize and starring Harrison Ford, adapted from the book by Paul Theroux.

Zaentz's following film, At Play in the Fields of the Lord, adapted by Jean-Claude Carrière from the book by Peter Matthiessen, shot by Hector Babenco on location in the Amazon Rainforest, continued Mosquito Coast's theme of the clash of Western values with the primitive.

In developing the project Zaentz resisted attempts by his backers to make the story more acceptable to a mainstream audience whereby they wanted him to cast Demi Moore in a leading role.

[16] In 1976, Zaentz acquired certain rights as regards The Lord of the Rings and The Hobbit from United Artists, who had in turn purchased them directly from Tolkien eight years prior.

[16] On August 18, 2022, Embracer Group announced that it had entered into an agreement to purchase Middle-earth Enterprises from The Saul Zaentz Company.

If the litigation were resolved by a court or by a settlement the original plan could proceed, but then New Line might need to reorganize to allow someone other than Shaye to deal with Jackson.

In December 2007 Variety reported that Zaentz was also suing New Line, alleging that the studio has refused to make records available so that he can confirm his profit-participation statements are accurate.

It housed Concord Music Group and Fantasy Studios as well the Berkeley Digital Film Institute and other media production companies.

[28] John Fogerty noted his death on his Facebook page by posting the music video for his song "Vanz Kant Danz".

[29] Michael Douglas paid tribute to Zaentz in an article in The Hollywood Reporter, saying: He was the epitome of an independent, with an incredible sense of material, and the courage to see it through.