During the height of the show's popularity, Edward Woodward was often approached on the street by people in need, with situations similar to those depicted in the show. He began carrying flyers with the phone numbers of social services organizations and legal clinics for them to contact.

Edward Woodward suffered a heart attack in the summer of 1987. Accordingly, the producers needed to find a quick replacement while Woodward recuperated. Robert Mitchum was brought on as an old friend of Robert McCall, who helped McCall's son search for his missing father in the two-part episode, "Mission: McCall". Richard Jordan was also brought on as embittered former operative Harley Gage, and stayed for eight more episodes.

Edward Woodward was nominated for an Emmy for Outstanding Lead Actor in a Drama Series five years in a row even though the show aired for four years. The final two episodes were burned off in August 1989, which made him eligible to be nominated in 1990 for the 1989-1990 season. NOTE: Even though the show ran for four seasons, it started in 1985, and ended in 1989. Therefore, his nominations were for 1985, 1986, 1987, 1988, and 1989. A total of one nomination per year.

The theme song for this show was written by Stewart Copeland, former drummer with the band The Police.

Martin Shaw, who gained fame on the British series The Professionals (1977), turned down the role of Robert McCall on this show.

It is said that Edward Woodward's appearance in The Wicker Man (1973) gained him this role. He had previously played the title role in Callan (1967), a grittily realistic British television drama about a secret service assassin.

McCall drove a black Jaguar, New York license plate number 5809 AUJ.

According to William Zabka (Scott McCall), there were talks of a spin-off series with his character in the starring role, but it never materialized.

Melissa Leo guest-starred in one episode of the series. In 2014, she co-starred in the theatrical film adaptation of the series, with Denzel Washington in the title role.

McCall's main weapon was a .380 Walther PPK/S. He also often uses a Desert Eagle Mark I.

McCall's phone number is 212-555-4200.

Twenty-five years after the series ended, Denzel Washington succeeded Edward Woodward in the role of Robert McCall in the film adaptation The Equalizer (2014), which was based on this show.

Edward Woodward won a Golden Globe in 1987 for his outstanding performance in the series.

In the Season 1 episode titled 'Desperately', Ray Sharkey guest starred as a hired gunman named Geoffrey Dryden. During the climactic final scenes when McCall attempts to get the assassin's attention, Edward Woodward accidentally shouts out the actor's real first name instead of the character's name. This mistake was never edited and "Ray!" can still be heard in the episode.

In the episode titled 'The Confirmation Day' from Season 1, there is a scene in which McCall returns a stolen delivery truck to a mob boss and his associates. Edward Woodward was actually behind the wheel for entire scene. So when the viewer sees the truck's rear tire hit the edge of the guardrail and bounce upward as the truck enters the vacant lot, that was really Woodward cutting the corner too close.

In the pilot episode, Edward Woodward played Robert McCall with a soft American accent. By the time a series was commissioned, he acted with his own English accent.

This series was spoofed in the 1988 Saturday-morning TV-series "Flip!" by "The Get-Even Guy": a recurring sketch whose central character was a teenage boy sporting a trench coat, dyed hair, and an affected UK accent. He regularly aided the plight of youngsters who were being treated unfairly and/or exploited by various authority figures (a high-school gym-teacher, a video store-clerk, and the like). The Get-Even Guy never carried a real weapon or seriously injured anyone, but rather used whatever was on hand to humiliate his adversary...such as an ordinary videocassette (the tape from which was used to hopelessly entangle the dastardly clerk) or regular gymnasium-equipment.

This series was about Robert McCall, who became The Equalizer, as he set out to help people who have been wronged by New York City's dangerous criminals, as McCall seeks redemption for his dark deeds as an Intelligence Agent.

Despite an obvious English accent and preferring to drive a Jaguar motor car, Robert McCall never really mentioned being British. Some characters would sometimes make light of his English background (some characters thought he was a tourist for example) but McCall never reciprocated this.

In the pilot, McCall has a pet Irish setter. After the pilot, the dog was never seen or referenced again in the series.

Producers originally considered both Ben Gazzara and Robert Culp for the role of Robert McCall.