- Pro Wrestler Kevin Nash had to cut his hair for his role. To explain the haircut to his wrestling fans, he "bet" his hair in a match against wrestler Chris Jericho.
- Before choosing Tampa as the location to both film and set the movie, the director also considered places such as Biloxi, Mississippi; Mobile, Alabama; New Orleans, Louisiana; and Galveston, Texas.
- The scene with the explosion in front of the Bank of America building was not adequately publicized and hundreds of people called 911 thinking it was an actual explosion.
- Five identical Pontiac GTOs were built (two were totally destroyed) for the movie. This muscle car was chosen the film to distance itself from the earlier Artisan version of The Punisher (1989) (in which action star Dolph Lundgren rode a motorcycle throughout).
- The Russian fight sequence was described on the set as the "Horrific Clown Show".
- With the supervision of a trainer, Thomas Jane worked out extensively for the role with two hours of weight lifting and cardio, sometimes twice a day and a rigorous diet of health shakes. Jane also trained with multiple firearms and weaponry.
- The words that Frank Castle writes near the end of the film, listing the bases of his vigilante philosophy in numbered order, form the beginning of his war journal, an ongoing diary of his campaign against organized crime. It was the basis for the long-running comic book "The Punisher War Journal".
- Rebecca Romijn revealed that in a scene where she sews up a knife wound on Thomas Jane, she pushes the needle too far in and ends up actually sewing a couple of stitches on Thomas Jane's body instead of just the prosthetic wound.
- The license plate on Frank Castle's car reads "Year One". This is the auto customizer that worked on the GTO. It was just a coincidence that The Punisher also had a Year One title.
- The bourbon Castle drinks throughout the film is "Wild Turkey". In the Jimmy Weeks subplot, we see Jimmy drinking the same brand.
- Originally, The Punisher was supposed to have a sidekick, David Lieberman, alias Microchip, the Intel man. He was written out as director Jonathan Hensleigh had an intense dislike of the character.
- The bounty hunter's actual name was Harry "Heck" Thornton but was truncated to avoid confusion with the actor Billy Bob Thornton. In Welcome Back Frank, he does not carry a guitar or sing.
- Micky Duka is heavily based on a character from the comic series, named Mickey Fondozzi, who worked as a mob informant for The Punisher.
- The Castle family house in Puerto Rico are really restrooms/changing rooms located in Honeymoon Island State Park, Dunedin, Florida. State Parks adhere to strict rules about color of their buildings, the restrooms/changing room where re-painted from their original grey to the colors seen in the movie, they remain that color since the movie was released.
- Jonathan Hensleigh actually knew someone who parked illegally for two years in Manhattan by using the same bogus fire hydrant ploy Frank Castle uses to keep Livia's parking space open during his schemes.
- In order to update the comic origin to present day, Frank Castle's military record was changed from Vietnam to the Gulf War
- In a subplot of the film, which was cut, Frank Castle finds out that Howard Saint got his information from his friend FBI Agent Jimmy Weeks. He eventually stalks him and drives Weeks to commit suicide. This was included in the extended DVD cut.
- When the teaser trailer was shown, there was negative reaction to the solid white skull logo which has been the character's trademark in the books. The costume designer changed it to a "worn-down" design that better suited Frank Castle's character in the film.
- A close up shot of a bodyguard getting hit in the head with a paper cutter was cut due to the MPAA saying it was "too real".
- Jonathan Hensleigh and Roy Scheider are neighbors in New York City, which is how Scheider was cast as Frank Castle, Sr.
- The exclusive club that Howard Saint owns is "Saints and Sinners".
- Thomas Jane's discolored thumbnail was the result of him slamming it in a door, and has nothing to do with the story.
- Castle's sidearm for the climactic firefight is a modified 1911-style .45 equipped with a compensator, extended safeties and slide stop, beveled magazine well, and adjustable sights.
- When Castle is readying himself to administer the coup de grace to Saint, he attaches a shoulder stock to a pistol. This is presumably supposed to be a Glock 18, a version of the Glock 17 9mm capable of fully automatic fire. This is uncertain, however, since the piece never appears again in the film.
- The weapon Castle uses in the final shootout is a Colt M4A1 carbine, a shortened version of the M16 rifle. Castle's is modified with a flat-top upper receiver with a Picatinny-type accessory rail, an M203 40mm grenade launcher , and an Aimpoint M68 Close Combat Optic.
- The knife that Frank takes from the man attempting to break into Joan's apartment is a Benchmade model 42 balisong. Frank also uses a Strider JW model and an Emerson Karambit.
- While filming a knife fight scene, Thomas Jane accidentally stabbed Kevin Nash.
- The "popsicle interrogation" scene was drawn from a nearly identical scene in Punisher War Zone #1 (1992) written by Chuck Dixon.
- The Punisher was created by comic book writer Gerry Conway for an issue of Amazing Spiderman. Conway himself has become a successful writer for television and film.
- The Saints and Sinners Club shootout between Frank Castle and Howard Saint's goons was originally longer, but was cut because of pacing and explicit bloodshed. The only two scenes that were altered because of violence were: 1: The point-blank head shot featured blood squirting from the back of a thug's head. 2: The scene in which a thug is dispatched by way of sawed-off shotgun was also cut. The original scene feature pieces of the thug being sprayed from his wounds.
- The original film with no edits or cuts clocked in at 2 hours and 56 minutes.
- Scenes were constantly scaled back or cut to meet budget requirements. Effects scenes were almost always done the old-fashioned way with old tricks replacing new CGI. Jonathan Hensleigh discusses this in the commentary track of the original DVD edition
- Tampa Bay Lightning hockey player Vincent Lecavalier and former Bucaneers football player John Lynch were originally in one of the first scenes of the movie that was eventually deleted.
- The house used as Howard Saint's mansion belonged to ex NBA player Matt Geiger at the time of filming.
- Wizard Magazine editor Jesse Thompson appeared as a customer in the diner where Frank and Joan were before Heck comes in. He was not in the final cut.
- Many of the characters, including Joan, Bumpo, Spacker Dave and The Russian, all come from the punisher series "Welcome Back, Frank", written by Garth Ennis and illustrated by Steve Dillon and Jimmy Palmiotti. Timothy Bradstreet illustrated the covers, along with the promotional posters for the movie.
- The guns Mickey and Bobby try to buy in the beginning of the movie are Heckler & Koch G36Cs, the compact version of the G36 assault rifle.
- Frank's tenement building is located at the corner of N. Nebraska Ave. and E. Zack St., directly across the street from the Tampa Amtrak station. It's a fairly well known local landmark due to it's unusual shape.
- Was originally slated to be a sequel with Thomas Jane returning as Frank Castle/The Punisher with Jonathan Hensleigh returning to direct it as well. The writing development had went on for three years but by 2007, both Jane and Hensleigh left due to creative differences and also the budget being cut. After they left, Lionsgate then decided bring in director Lexi Alexander and actor Ray Stevenson to play The Punisher and rebooted the film into what is now Punisher: War Zone (2008).
- Second film in which Samantha Mathis plays the love interest of the hero and John Travolta plays the villain. The first was Broken Arrow (1996).
>>> WARNING: Here Be Spoilers <<<
Trivia items below here contain information that may give away important plot points. You may not want to read any further if you've not already seen this title.
- SPOILER: In the script, Livia Saint was supposed to commit suicide and not be killed by Howard Saint. She died the same way showed in the movie, but in the script she willingly threw herself off the bridge.
- SPOILER: The scene in which hot oil is tossed on to The Russian was scaled back due to excessive violence. Originally, blood was supposed to pour from The Russian's eyes, but it was deemed "too much" by the MPAA.
Related Links