Hal Needham asked Jerry Reed to write a theme song for the film. A couple of hours later, Reed presented "East Bound and Down" to Needham. With an acoustic guitar, Reed started to play it and Needham immediately stopped him. Thinking Needham didn't like it, Reed offered to re-write the song. To which Needham replied: "If you change one note, I'll kill you!" The song went on to become one of Reed's biggest hits.
Jackie Gleason said that his cafe' scene with Burt Reynolds was not in the original story; it was Gleason's idea.
Most of Sheriff Buford T. Justice's lines were improvised.
Adding the Junior Justice character was Jackie Gleason's idea. "I can't be in the car alone," Gleason said. "Put someone in there with me to play off of."
Buford T. Justice was the name of a real Florida Highway Patrolman known to Burt Reynolds's father, who was once Chief of Police of Jupiter, Florida.