Carroll O'Connor wrote several scripts, under the pseudonym Matt Harris, for the show and two "In the Heat of the Night" movies. He worked under the pseudonym concerned that his scripts would not be received well by television critics.
The beautiful, white house Bill Gillespie bought at the start of season 7 was an actual residence in Covington, GA. After the series ended, it sat empty and neglected for years, with one fan reportedly describing it as "falling to pieces". It has since been purchased again and has been beautifully remodeled.
The season 7 episode "Every Man's Family" was meant as the pilot for a proposed spinoff for the character of Bubba Skinner. The network did not have any available slots at the time it was first broadcast and In the Heat of the Night ended soon after, so the spinoff never materialized. It would have been set in Atlanta.
During the period when Howard E. Rollins Jr. was in rehab, Virgil was said to be in New Orleans working with the F.B.I.. Also, when Carroll O'Connor was recovering from heart surgery, his absence was explained by having him attend a police convention.
The 1989 season was played slightly out of order. The previous season ended with a cliffhanger. However, Carroll O'Connor, who also served as executive producer, wanted to begin the next season with the episode in which Althea Tibbs is raped because he felt that that particular episode had a strong message and that it should be the season opener. The continuation to the cliffhanger was shown a few episodes into that season with Gillespie recapping the events of what happened when he was kidnapped and the events surrounding that period.
Bubba's first name was never revealed, although in print, he was sometimes referred to as V. L. "Bubba" Skinner. In fact, in the episode "A Small War", when he was asked if he had a first name, his response was "Yes mam, i do. But "Bubba" will do just fine".
The building used for exterior shots of the Sparta Police Department was actually the Newton County Library (later re-named the Porter Memorial Library) on Monticello Street in Covington, GA. Since the show ended, it has been home to various medical equipment supply companies. Interior shots of the Sparta PD were shot on a set built on a soundstage in an industrial building a couple blocks over.
The season after Howard E. Rollins Jr. left the cast, he did return for several guest appearances. However, Anne-Marie Johnson, who played Althea, didn't. Her absence was explained by having Althea leave Virgil because of her having emotional problems stemming not only from her rape, but the stress of her being married to a policeman.