In the theatrical version of the film, Methos refers to the Sanctuary as Holy Ground. Many fans were upset that Kell killed Immortals on Holy Ground with no consequences, So all references to the Sanctuary as Holy Ground were deleted from the DVD version of the movie.
Originally meant to act as a bridge between Highlander (1992) and the spin-off series Highlander: The Raven (1998) continuing on TV. These plans started to go awry when "Highlander: The Raven" was canceled, and production delays started occurring due to cast availability problems. Dimension Films, who had taken on the project as a way of invigorating the franchise, soon realized that their plans for the film were not going to meet expectations and scaled back on its release, effectively throwing the movie away.
The interior of the Sanctuary was actually an abandoned salt mine 200 yards below ground in Romania. The only access to the mine was a single elevator, and the crew had to be transported down a few at a time.
The scene of the village burning was originally shot to show Connor deliberately setting the fire in his fit of rage. The producers later decided that Connor would not be cruel enough to do this, and the scene was edited to make it appear that the fire starts incidentally.
In the video and DVD releases, the "JVC" logo originally seen in the rooftop scene in the theatrical cut has been airbrushed out. This is because the producers believed it to be "too distracting". They also claim that this particular product placement was unintentional.
In the beginning of the movie, Jacob Kell has 661 kills. At "the last supper" (which can be understood as the metaphore of the Jesus's last supper) he kills five more immortals. That makes him the immortal with 666 kills. Which is the number of the devil.
During the fight Connor and Duncan have with the "Tax" thieves one of the men (Lachlan) picks up a rock as a weapon. As the McLeods go on the defensive Duncan says to Lachlan "Looks like you've lost the edge, lad". This is a reference to Adam Copeland's (Lachlan) "stage" name of Edge in the World Wrestling Entertainment.
There are four shots in this film from the original Highlander (1986). The first is a computer-altered and -enhanced shot of Glenfinnin, which was originally the shot of Connor walking away from his village. The second is a shot of the Silvercup sign, pulled from the scene of the Kurgan taking Brenda to the building. And in the rooftop Quickening, two shots of Connor and Heather together are also taken from the original.
The broadswords used by Connor and Duncan as they spar in the flashback are Federschwerts, a German training sword first introduced in the late 1500's. They are not reproductions of the Kurgan's sword as some thought.
For the scene in the cemetery where they meet following the events at the Sanctuary, Duncan and Connor originally spoke French, because both Paul and Lambert are fluent. However, during post-production it was decided to switch the language over to Scottish Gaelic.
Connor MacLeod's "Trophy Room" from the first film was reconstructed in detail here, though the hardwood floor is different. The original set had a radial central floor which supported the weight of MacLeod's old blacksmith's anvil in the middle.
The character of Jin Ke is very loosely based on a real historical person - Jing Ke. He was a guest residing in the estates of Dan, crown prince of Yan and renowned for his failed assassination of the Chinese emperor Qin Shi Huang who reigned from 221 BC to 210 BC.
Highlander (1986) writer Gregory Widen worked on early drafts of the script and was in talks to direct. Portions of Widen's writing were used for the film, though he only received a "characters" credit.
Earlier drafts of the script differed greatly from the final cut in several aspects. The character of Kate was originally named Alexis, most of the flashbacks occurred in Shanghai China instead of Ireland. Methos and Duncan were living in Paris rather than London as they did in the end of the TV series. Hugh Fitzcairn and May Ling Shen were to appear in the Shanghai flashbacks.
The trivia item below may give away important plot points.
Jin Ke's fate during the "Last Supper" scene was shot differently than the way it was edited to appear. Originally, Jin Ke stabs his sword into a wall and beheads himself after realizing that he cannot beat Kell, denying Kell the opportunity of killing him. In the theatrical cut and the DVD "producers' cut," the scene was edited to make it appear that Kell beheads Jin Ke (off-screen) along with the rest of the group. The original version of the scene with Jin Ke beheading himself can be seen in the rough cut of the film included as a special feature on Disc 2 of the Region 1 DVD.