Burt Reynolds broke his coccyx while going down the rapids when the canoe capsizes. Originally, a cloth dummy was used, but it looked too much "like a dummy going over a waterfall". After Reynolds was injured and recuperating, he asked, "How did it look?" The director replied, "Like a dummy going over a waterfall."
According to Turner Classic Movies, John Boorman wanted Lee Marvin and Marlon Brando to play Ed and Lewis, respectively. After reading the script, Marvin suggested that he and Brando were too old, and that Boorman should use younger actors instead. Boorman agreed, and cast Jon Voight and Burt Reynolds.
Ned Beatty was the only one of the four main actors to ever have paddled a canoe prior to shooting the movie, which is ironic since his character is the most inept and clumsy. The others learned on set.
Billy Redden, the boy with the banjo liked Ronny Cox, and disliked Ned Beatty. When at the end of the dueling banjos scene, the script called for Billy to harden his expression towards Drew Ballinger, Cox's character, he was unable to fake dislike for Cox. To solve the problem, they got Beatty to step towards Billy at the close of the shot. As Beatty approached, Billy hardened his expression and looked away - exactly as intended.
The movie was shot primarily on the Chattooga River, dividing South Carolina and Georgia. Additional scenes were shot on the Tallulah Gorge in Georgia as well in Salem, South Carolina and Sylva, North Carolina. Monaca, Pennsylvania is represented in shots of the town which did not call for the actors to be present.
The cliff climbing scene was shot "day for night", meaning that the footage was shot during the day and underexposed with a bluish tint (in post-production). Because film stocks were so slow (up until the late 1970s), and the anamorphic lenses were slow (didn't let in as much light as spherical lenses), and a plethora of lights were often needed, day for night was common practice for many films with night scenes during that period of filmmaking. Faster film stock has made the technique less common.
Credited with the first recording of "Dueling Banjos" (its most common title, also known as "Feudin' Banjos" and "The Battle Of The Banjos") is Don Wayne Reno and Arthur Smith. Prior to "Deliverance" both parts were played with banjos, and it is the same speed all the way through. Almost all modern bluegrass bands play the "Deliverance" version in the key of G. In the movie both the guitarist and banjo players have capos on the second fret, denoting it is in the key of A.
John Boorman was looking for an actor to play the toothless one of the pair of murderous hillbillies. Burt Reynolds suggested Herbert 'Cowboy' Coward, who had no front teeth, stuttered and was illiterate. Reynolds had worked with Coward in a Wild West show in Maggie Valley, NC.
Unlike Ronny Cox with his guitar, actor Billy Redden did not know how to play banjo for the famous "Duelling Banjos" scene. To simulate the realistic chord playing on the banjo, another boy, who was a skilled banjo-player, played the chords with his arm reaching around at Redden's side while Redden picked. On the soundtrack, musicians Eric Weissberg and Steve Mandel are actually playing.
According to director John Boorman, the jig done by the filling station attendant during the "Dueling Banjos" sequence was unscripted and spontaneous on the part of the actor.
This movie is in film history considered to be the "breakthrough" film of Burt Reynolds. By breakthrough, it marked his transition from acting and starring into super-stardom. This film reflects the start of the period of Reynolds enormous star power and box-office pulling power, his machismo persona being mixed with a critical recognized serious dramatic performance.
Bill McKinney became so identified with his chilling role as the Mountain Man that he adopted www.squeallikeapig.com as the name of his official website.
The aluminum canoe has the blue and white logo of Grumman, the famed aircraft company and builder of such craft as the F-14 Tomcat and the Apollo Lunar Module.
The trivia items below may give away important plot points.
An alternate ending was shot, but cut from the final version. This other ending apparently takes place a few weeks (or perhaps months) after the main events of the movie. It appears in author/screenwriter James Dickey's original script as part of the final "dream" sequence, but not as the story's literal conclusion. The scene shows Lewis, Burt Reynolds, walking with a crutch (in Dickey's screenplay, his leg is supposed to be amputated below the knee). The sequence depicts Ed, Jon Voight, Lewis and Bobby, Ned Beatty, meeting with Sheriff Bullard, James Dickey, near the dam in Aintry. The sheriff displays to them a body placed on a stretcher and uncovers it, so that they can look at its face. No identifiable details of the body are shown, which was a deliberate choice, to make the audience uncertain whether the dead man is Drew, Ronny Cox, Don Job, Bill McKinney, or the Toothless Man, Herbert 'Cowboy' Coward. The body was played by Christopher Dickey (James Dickey's son), who writes about the scene in his memoir, "Summer of Deliverance", and even HE doesn't know whose body it was supposed to be. In the screenplay, Ed awakens terrified from this dream, just before the face of the corpse is to be revealed.
John Boorman was under great pressure to cut most of Bill McKinney's death scene, but argued for it and ultimately only deleted six frames (one quarter of a second.)
Ronny Cox's shoulder is double-jointed and it was he that suggested to director John Boorman that his arm appear twisted around his neck when his body is discovered. No prosthetic was used.
The infamous scene in which Bobby (played by Ned Beatty) is raped and ordered to "squeal like a pig" by the hillbilly played by Bill McKinney was somewhat improvised. The novel and original screenplay detailed the rape with no porcine lines. Beatty later claimed credit for the pig idea, but Christopher Dickey, son of author James Dickey, stated in his book "Summer of Deliverance" that the line was suggested by a crewman.