This movie was the first one Columbia Pictures filmed after it moved onto the Warner Brothers lot in 1972, creating The Burbank Studios, to facilitate both production companies. The castle set from Camelot (1967) was recycled as Shangri-La. The medieval turrets were removed and replaced with Tibetan gables to simulate Himalayan Buddhist monasteries. Most of the castle's lower levels remained intact, and the courtyard was replaced with layered steppes and fountains. The set remained on the studio's backlot for several years before it was torn down to make way for a new office building.

In a 1975 magazine interview with Rona Barrett, producer Ross Hunter acknowledged the failure of the soundtrack. "When we hired Bacharach and David to write the songs, we didn't know they were on the verge of dissolving their partnership. When they finally delivered the music, we were already deep into pre-production. We knew it was a bum score, but we couldn't do anything about it."

Pierre Cardin put out a line of costume jewelry, watches and belts "inspired by Lost Horizon". Marrakech, Ltd. had a line of "Lost Horizon" shirts for men, Periphery a line of women's attire, Rijir a line of colognes and soaps, and Brown Jordan a line of rattan furniture all designed for that Shangri-La look. Craft Masters put out a paint-by-number set, and Saalfield marketed a "Lost Horizon" coloring book.

This movie was one of the few mainstream American movies of the 1970s that was never released on VHS in the U.S. A Limited Edition LaserDisc release in the early 1990s was the only U.S. home video release until 2011, when Sony released the movie on DVD.

Julie Andrews, Jean Arthur, and Barbara Stanwyck turned down the role of the teacher.

Touring back-up singer and session vocalist Jerry Whitman was contractually obligated not to reveal his vocal participation. "They didn't want me capitalizing on it or putting out a press release", Whitman said. "But the movie turned out to be such a bomb, I don't think anyone would care if I talk about it now."

Michael York has said that despite producer Ross Hunter's reputation for lush productions, York found the decor tacky. The lamasery scenes were filmed in Burbank during a hot summer, and York began to call the location "Shangri-La in the smog".

Professional vocalists Jerry Whitman and Diana Lee provided the singing voices for Peter Finch and Liv Ullmann, respectively. They also sang on the Disneyland Records release "The World Is A Circle", which featured a handful of songs from this movie, plus other show tunes.

A television special promoting the movie aired in 1973. Sir Richard Harris and Sammy Davis Jr. were among the stars.

This was producer Ross Hunter's first movie for Columbia Pictures after producing a string of hits for Universal Pictures over twenty years, including Imitation of Life (1959), Madame X (1966), and Airport (1970). After its huge commercial failure, it was his last.

This movie is listed among the 100 Most Enjoyably Bad Movies Ever Made in Golden Raspberry Award founder John Wilson's book "The Official Razzie Movie Guide."

A fertility dance number was cut from the final print because preview audiences laughed at it. The scene was later restored.

This movie was a box-office and critical failure. Esquire Magazine called it "The worst movie of the year". Cue critic William Wolf called it "Atrocious, lame-brained, some six million dollars was spent on this worst-of-worst remake."

John Gielgud's letters, published in 2004, make several references to the filming. To Dame Edith Evans he wrote in April 1972: "The part is an idiotic walkabout, not a moment that gives one the slightest opportunity to act and I feel a bit ashamed of the bribery that makes me accept it. But I had a bad income tax disaster three years ago and this should help to put me straight again". Elsewhere he describes Chang as 'a very stupid part' and that his costume and shaved head made him feel like a Tibetan version of Portia in the trial scene from The Merchant of Venice "with a hint of Von Stroheim's grandson by Yul Brynner".

Gielgud found the heat on location unbearable. "Yards of fox fur for the blizzard scene to be shot... in blazing heat. I shall strip beneath the coat in order to survive". Later: "I did five days gruelling work on the canyon set, swathed in my furs, wind machines hurling plastic snow in our faces and appallingly uncomfortable and hot". However, he enjoyed staying in Gladys Cooper's former bungalow in Santa Monica, and also his 'fine caravan' at the Fox Ranch- "Colour TV, air conditioning, a folding bed and of course, a loo! So I don't think I can complain of un-star treatment!".

So many backers lost at least half of their investments, that the movie became known in the industry as "The Lost Investment".

In a letter to his partner Paul Anstee in April 1972, Gielgud wrote: "The film is going to cost 6 million dollars, so let's hope the music will be the making of it- nothing else will! I have christened it 'Hello, Dalai'!".

Yellow flowers planted on the set withered in the heat and had to be individually hand-painted back to the original colour to match footage already shot.

George Kennedy later said he did not like working with John Gielgud.

Producer Ross Hunter offered the role of Chang to Toshirô Mifune, but he turned it down.

The cast includes three Oscar winners: Peter Finch, George Kennedy, and Sir John Gielgud; and three Oscar nominees: Liv Ullmann, Sally Kellerman, and Charles Boyer.

Michael York and Olivia Hussey appeared in Romeo and Juliet (1968).

Included in "The Fifty Worst Films of All Time (and How They Got That Way)" by Harry Medved and Randy Lowell.

This was the last screenplay for a theatrical movie written by Larry Kramer. In Larry Kramer in Love and Anger (2015), the writer revealed that he wasn't proud of his script for this movie, and in 2002 said, "It was the one thing I have done in my life that I truly regret. People still laugh about it." But Kramer also acknowledges that the nearly $300,000 he earned for his script (along with great investments his lawyer brother made with the money) left him free of financial worries for the rest of his life. He became a successful playwright and a legendary LGBT rights activist.

This movie was supposed to go to the British Royal Family for a private screening before general release in the U.K.

Robert Shaw was originally offered the part of Richard Conway.

Woody Allen joked that his biggest regret in life was buying a ticket for this movie.

This film inspired Bette Midler's oft-quoted quip, "I never miss a Liv Ullmann musical."

Hollywood legend claims that when this movie was screened for an industry audience just prior to its release, about half of those in attendance walked out. Among the many celebrities heading for the exits was Doris Day, whose most successful movie Pillow Talk (1959) had also been financed by this movie's producer Ross Hunter.

The first half hour of this film replicates, almost shot-for-shot, Frank Capra's 1937 original production of Lost Horizon. This musical remake was "green-lighted" despite the previous version having taken years to recoup its cost for Columbia Pictures.

This film failed so spectacularly at the worldwide box office that for several years afterward, no major Hollywood studio would even consider producing a musical of any kind.

Closing credits: The characters and incidents portrayed and the names used herein are fictitious and any similarity to the name, character or history of any person is entirely coincidental and unintentional.