Right before shooting was set to begin, Pat Hingle suffered devastating injuries when he accidentally fell 54 feet down an elevator shaft in his apartment building. It would take Hingle over a year to fully recover from the accident. In the meantime, however, he decided to go ahead and do the film - he would simply incorporate his limp into the character. "I broke everything," Hingle said later. "I landed upright, so I broke hips and knees and ankles and ribs, and that sort of thing. That lurching walk that Ace Stamper has - that was as good as I could walk."

Depicts the first French kiss in a Hollywood film. It occurs between Warren Beatty (Bud) and Jan Norris (Juanita) during the waterfall scene.

For the scene in which Deanie tries to drown herself in the lake, Natalie Wood asked Elia Kazan if she could do it in a controlled studio tank because she had a great fear of water - particularly dark water. "I assured her it was a very shallow lake and that her feet would always be close to the bottom," said Kazan. "She said that even if her feet were on the bottom, she'd be in a panic of fear about it. So I asked my assistant, Charlie Maguire, to get into the water with her, just out of camera range, while she played the scene of struggling to save herself. This didn't entirely reassure her, but she did the scene and did it well - then clutched Charlie. 'Cut!' I cried. On dry land she continued to shake with fear, then laughed hysterically, with relief."

Even though they were supposed to be playing teenagers, Natalie Wood and Warren Beatty were approximately 22 and 23 respectively at the time of filming. As a result, Elia Kazan decided that the other actors who were to play teenagers in the film should be in their early to mid-twenties as a way to make it easier for the audience to accept Wood and Beatty as teenagers rather than as adults playing teens.

The film's title comes from the poem, "Ode: Intimations of Immortality" by William Wordsworth: "Though nothing can bring back the hour of splendour in the grass, / of glory in the flower, / we will grieve not, / rather find strength in what remains behind."

In the bath scene, Natalie Wood's wrist is very briefly revealed. She normally always wore a bulky bracelet or long sleeves to hide the protrusion of a bone in her wrist which she thought to be an ugly anomaly.

Jane Fonda wrote in her autobiography that she tested for the role of Deanie. When Elia Kazan asked her if she was ambitious, she said no (even though she was) because "good girls aren't supposed to be ambitious." Fonda believes this was the reason for her not getting the role.

Pat Hingle, who plays Warren Beatty's father, was in fact only 13 years older than Beatty.

Film debuts of Warren Beatty, Sandy Dennis, Phyllis Diller, Marla Adams and Eugene Roche.

As filmed, this film included a sequence in which Wilma Dean Loomis takes a bath while arguing with her mother. The bickering finally becomes so intense that Wilma jumps out of the tub and runs nude down a hallway to her bedroom, where the camera cuts to a close-up of her bare legs kicking hysterically on the mattress. Both the Hollywood censors and the Catholic Legion Of Decency objected to the hallway scene, finding the bare backside unsuitable for public display. Consequently, director Elia Kazan dropped the piece, leaving an abrupt jump from tub to bed. Later, in an early 1970s TV interview with Mike Douglas, Wood claimed that the European cut of the film she eventually saw in France left in the partial nudity scene in the hallway.

Dennis Hopper was considered for the role of Bud Stamper.

Film neophyte Warren Beatty looked at Elia Kazan as a teacher and sought to learn as much as possible from him. Kazan taught him how to think about acting, where to put the camera, how to break down a script - all valuable lessons for Beatty, who later went on to direct and produce himself.

Natalie Wood's sister Lana Wood had an on-again, off-again relationship with Warren Beatty for several years after he and Natalie had broken up. In December 1981, a few days after Natalie's funeral (which Beatty did not attend), Lana met up with him to discuss a project. She recalled that "Natalie was not mentioned until I was about to leave, and then I couldn't help it. I wanted him to say something about her, to say how he would remember her." Lana asked Warren if he missed Natalie, to which he replied "No, not really. She's gone and I'm sorry, but that's it. The truth is that I talked to you and know you better." Then "he reached out and pulled me to him. Warren simply could not let the opportunity get by. This time I could, though." Angered by his lack of sensitivity, she said her last goodbye and ran out the door.

Natalie Wood announced her separation from then-husband Robert Wagner in June 1961. Soon after, she began publicly dating Warren Beatty, but said nothing to dispel the general public's assumption that her marriage to Wagner had ended because she and Beatty were already having an affair beforehand. This long-held misconception was obliterated in 2001 when author and former lawyer Suzanne Finstad emphatically wrote in her bestselling biography "Natasha" that Wood left Wagner after discovering him in a compromising position with another MAN. Through representatives, Wagner has denied Finstad's claim. Finstad, however, stands by her account in the book and has reiterated the claim in documentary interviews. According to Finstad, Wood idly allowed gossip magazines to purport the false rumor that she'd been a cheating wife in order to help Wagner save face over his bisexuality, which certainly would've ruined his career if it had become public knowledge at that time. In other words, Wood's "affair" with Beatty served as a convenient smokescreen for Wagner. In September 2018, 17 years after its original publication in Finstad's book, the allegation was again made during a two-part episode of Dr. Phil (2002) on which Natalie's sister Lana Wood appeared, Dr. Phil: Mystery at Sea: What Happened to Actress Natalie Wood? (2018)--perhaps the first time the claim has been spoken out loud on broadcast television.

The title character in Judy Blume's coming-of-age novel, Deenie, was named for Natalie Wood's character in this film. The novel contains several references to the film.

Elia Kazan did whatever was necessary in order to bring out the best possible performances by his actors - it was one of the reasons he was known as one of the best directors in the business. From the beginning, he wanted to strip away the Hollywood glamour from Natalie Wood and get her to a more natural state for the camera, which was appropriate for the character of Deanie. It meant that Wood had to do without the sophisticated makeup and costumes she was used to, which caused her some anxiety. According her friend Mart Crowley, she was always trying to sneak on a little extra rouge or lipstick when Kazan wasn't looking.

Although Elia Kazan had planned to film the movie in Kansas, a severe drought forced him to relocate all shooting to New York state. The waterfall in the film is located in High Falls, New York, in the Catskills.

According to one of the makeup artists, the crew found Warren Beatty arrogant and didn't like him. In fact, he was given the nickname "Mental Anguish" or "M.A." for short that crew members called him behind his back.

The nightclub owner played by Phyllis Diller is Texas Guinan, a real-life New York nightclub owner of the 1920's. "Hello, suckers!" was her standard nightly greeting to her nightclub patrons.

The very brief glimpse we get of a building in Yale is not Yale, but CCNY, the City College of New York.

Natalie Wood's character tries to drown herself. 21 years later, Wood drowned after falling off a boat.

Elia Kazan and Barbara Loden were a couple during filming. They had begun their affair several years earlier and had to keep it under wraps since Kazan was married to someone else at the time.

Incredibly - by today's standards - a Cedar Rapids, Iowa (USA) newspaper ad for this film says "No one under 16 will be admitted unless accompanied by an adult".

There were two scenes that worried Natalie Wood due to the intensity of each: the scene where she has a confrontation with her mother while she is in the bathtub; and the scene in which she tries to drown herself in a lake after Bud rejects her sexual advances. Each time, Elia Kazan found a way to bring out her best, even if his methods left her angry. "The bathtub scene, in which I was to be hysterical," said Wood in a later interview, "always frightened me. And I told Kazan I was very worried about it. His response absolutely threw me for a loop, because he said, 'What you do, I'll let you see the film, and we'll go back and do it again. Or we can play it on Audrey's [Christie] reactions.' And I was so enraged and offended that I became hysterical. That was his way of dealing with me, and it was obviously the correct way, because we only shot it once."

Elia Kazan wasn't that enamoured with Warren Beatty, though he couldn't deny that he was very talented. "Warren was a little 'snotty' - I don't know a better word for how he behaved and can't find one in my thesaurus," said Kazan in his 1988 autobiography A Life, "but he was able to grow into a formidable man."

Shot entirely in New York, exteriors were filmed in Staten Island and upstate New York, which doubled as Kansas in the 1920s. Interiors were filmed at Filmways Studios in East Harlem.

Included among the "1001 Movies You Must See Before You Die", edited by Steven Schneider.

The film takes place from 1928 to 1931.

It is revealed that Bud's real name is actually Arthur.

While a clip was not actually seen (though dialog is heard), there is a scene in Pedro Almodóvar's What Have I Done to Deserve This? (1984) in which the grandmother and her eldest grandson attend a showing of Splendor in the Grass (1961). As they leave the theater, the poster (Spanish) is clearly seen in the background.

The NY club which Bud and Ace go to is similar to the '300 club' run by flapper Texas Guinan in the 20s. She would often greet guests with the phrase: "Hello suckers".

Included among the American Film Institute's 1998 list of the 400 movies nominated for the Top 100 Greatest American Movies.

Favourite film of Lesley Ann Warren.

Diane Varsi and Lee Remick were considered for the part of Deanie.

Jody McCrea and Troy Donahue were considered for the part of Bud.

The exterior used for Yale is actually The City of New York's Shepard Hall located in Harlem, New York.