The script was originally offered to Clint Eastwood as the fourth Dirty Harry film with a working title of "Dirty Harry IV: Code of Silence". but Eastwood turned it down. In 1979, the screenplay had been written and offered to Warner Bros., the studio that made the "Dirty Harry" movies. The fourth installment in that film franchise ended up being another movie instead which was Sudden Impact (1983). Eastwood already was working on Pale Rider (1985) the same year with the same screen writers of this film.

The scene where the two hoods walk into the tavern to rob it, only to find that it's full of cops is based on an actual event that took place in an infamous after-hours bar on Chicago's near North Side where policemen gathered after their shifts. Among the cast are several veterans of the Chicago Police force including Dennis Farina.

Considered as something of a comeback-vehicle for Kris Kristofferson after the disaster of Michael Cimino's Heaven's Gate (1980). Kristofferson found it way too violent and did Flashpoint (1984) instead. That movie was made a year before this picture and was written by the same two screenwriter who wrote this film.

This is the first movie where Ron Dean and Joseph F. Kosala, whose play Brennan and Kobas, played together. Later they met again in Above the Law (1988), The Fugitive (1993) and Chain Reaction (1996), all directed by Andrew Davis.

The script was written for both Clint Eastwood and Kris Kristofferson but they both turned it down. Ironically, the screenwriters who wrote the story for this film also wrote Pale Rider (1985) and Flashpoint (1984) in which Eastwood and Kristofferson each starred in respectively.

The building that the Luna Gang used to stage the raid on the Camacho drug house, was actually owned by two Chicago Police Officers.

Actor Dennis Farina, who plays the cop Detective Dorato, was actually working as a real life police officer in Chicago, Illinois during the production of this picture.

First action cinema movie of director Andrew Davis who would go on to direct many action movies such as The Fugitive (1993), Under Siege (1992), The Package (1989), Collateral Damage (2002), and Above the Law (1988).

After the film in development was passed over by Clint Eastwood and the Warner Bros. studio, an 18th June 1980 article in show-business trade paper 'Variety' reported "Slott has "Code Of Silence," a $7,000,000 thriller about a cop". The Wikipedia website states that this story reported "the script was briefly in the possession of Canadian producer Gene Slott, who was looking to make it in 1980."

One of Chuck Norris personal favorite films he ever did.

This film was labeled Chuck Norris "own version of Dirty Harry (1971)" by the New York Times and was generally perceived as this publicly by audiences just as the recent Sharky's Machine (1981) had been considered Burt Reynolds' version of Dirty Harry (1971).

The picture went to the No. #1 spot at the American box-office when it debuted stateside there in the USA in early May 1985.

One of two cinema movies that action star Chuck Norris starred in that were first released in theaters in the year of 1985. The two theatrical feature films are Code of Silence (1985) and Invasion U.S.A. (1985).

The production "bought the script for a whopping [US] $800,000" according to Ron Base in a 11th February 1986 article published in the 'Toronto Star' newspaper. This was, according to the piece, "more than the total cost of a lot of Chuck Norris movies".

The meaning of the movie's "Code of Silence" title, according to a definition at the Wikipedia website, "is a condition in effect when a person opts to withhold what is believed to be vital or important information voluntarily or involuntarily." In the picture, it is also referred to as "nobody talks" and "Omertà", with the same web source defining the latter as a Mafia term, "a code of silence about criminal activity and a refusal to give evidence to the police."

The nick-name of Tony Luna aka Anthony Luna (Mike Genovese) was "Crazy Tony" whilst the nick-name on the street of Chicago Police Sergeant Eddie Cusack (Chuck Norris) was "Stainless Steel".

Unlike earlier Chuck Norris action movies, this picture contained much less use of martial arts in the picture.

At the American box-office, at the time this movie was first released in cinemas, this film became the second most financially successful Chuck Norris picture after Missing in Action (1984).

This action movie was nominated for the American Film Institute's "100 Years . . . 100 Thrills" list in 2001.

This Dirty Harry (1971) style movie, based on a script originally intended to be that franchise's third sequel, referencing both that picture and the name of Code of Silence (1985)'s star Chuck Norris, this flick was jokingly nick-named "Dirty Chuckie" by film critic Leonard Maltin.

Debut theatrical feature film of both actor Joe Guzaldo and actress Molly Hagan.

In both of two of the Dirty Harry (1971)-style movies made during the early-mid 1980s, Sharky's Machine (1981), set in Atlanta starring Burt Reynolds, and Code of Silence (1985), set in Chicago and starring Chuck Norris, the arch-villain in both of these movies was portrayed by actor Henry Silva.

Jeff Bridges, Charles Bronson, Harrison Ford, Mel Gibson, Gene Hackman, Tommy Lee Jones, Nick Nolte, Kurt Russell and Jon Voight were considered for Eddie Cusack.

The name of the new police three-axle remote-controlled rocket-equipped crime-fighting robot tank was "The Prowler".

The picture utilized the talents of twenty-seven stuntmen as well as action star Chuck Norris according to show-business trade paper 'Variety'.

Actress Molly Hagan and actor Joe Guzaldo both received 'introducing' credits.

The "Prowler" police robot in the picture, according to the movie's closing credits, was "provided by Robot Defense Systems, Inc. Thornton, Colorado".

The pinball machine visible in the pool hall is Bally's Playboy from 1978.

Action star actor Chuck Norris sports a beard in this major motion picture as he had done previously in Lone Wolf McQuade (1983).

Technical specifications, armory, and gadgets that featured on the Prowler police tactical assistance robot included a Doppler radar, one M-40 recoil-less rifle, infra-red heat sensors, two Mark 19 grenade launchers, and twin HB .50 caliber machine-guns. The robot featured a simplified Mark 2 hand-held control system which utilized a remote control hand-controller. "The Prowler" also featured both a target acquisition system and a laser range & guidance system.

Andrew Davis: [protagonist smashing someone's head on drug table]

Body Count: 47.

The place where the limousine explodes after the car chase is the same place the S.W.A.T. van flies out during the truck chase in The Dark Knight (2008).

The film makes more than one reference to a "Colomban Necktie" which dialogue in the movie defines as a death where a throat is slashed and the tongue is then pulled-out to hang through the neck.