Goofs

The vigilante drives a 1978 Firebird Trans Am, which soon turns into a 1979 Firebird Formula.

Also.. when the vigilante grabs his gun and goes to confront the Kurgan, he leaves the headlights on, but in several later shots the headlights are off.

When the Kurgan and Brenda look at the Silvercup building from the bridge, the sign says "Silvercup Studios." When MacLeod and the Kurgan fight on top of the building, the sign simply says "Silvercup."

Fasil loses his mirrored sunglasses, but soon has them back.

Just before Connor arrives at Brenda's apartment for dinner you see her place a gun in the second from the top drawer of a small chest. When Connor arrives and walks into the room he goes to the chest and opens the top drawer, removes the gun and holds it up.

Speed of Sean Connery's legs moving when he runs along the beach VERY different to that of the stunt double's.

Brenda uses a metal detector to find particles of a sword in reinforced concrete. This cannot work as the signal from the metal in the reinforcement bars would swamp the signal generated by the sword particles.

The character of Garfield, the uniformed NYPD officer who fights with MacLeod, wears a sergeant's stripes but his cap and badge are that of a patrolman. A NYPD sergeant would have a gold badge and cap insignia, not silver.

During the fight under Madison Square Gardens, several car windshields are broken. In every case the glass shatters into pieces, which is impossible as all car windshields are laminated with a layer of plastic in order to prevent just this for safety reasons.

When Kurgan is fighting Ramirez (in the 16th century), he is using his modern, detachable high-tech sword. Even the fissure where the blade is divided can clearly be seen in several takes.

Lieutenant Moran, while questioning MacLeod, refers to a Toledo Salamanca Broadsword. The Toledo Salamanca is actually a rapier sword.

Connor conceals his katana inside his trench coat, yet he is able to move around, sit and even remove the coat all without showing any sign of the concealed sword. This became a trope in successive Highlander productions, leading to the colloquial term "katana space" coined by fans as a tongue-in-cheek in-universe explanation for a production assistant handing the actor a sword just before a fight scene.

The Kurgan slices the roof off a Chevrolet Mailbu/Chevelle but when it emerges from the alley it becomes a Plymouth Duster.

Immortals aren't invulnerable. But when Connor is shot from behind by a German with a submachine gun, there is no blood on the back of his shirt, plus there are no bullet holes in the shirt.

The face of Christopher Lambert's stunt double is clearly visible for several seconds when MacLeod slides down the wire during the rooftop fight.

When the Silvercup sign falls forward, the support wires in front of it remain taut, showing that the crew are pulling the sign down.

When Brenda tests the sample of Connor's sword, she says, "It was folded over 200 times." Even if you could keep the layers from being forge welded back together, folding a bar stock for a sword so many times would create layers so thin they would have almost no structural integrity. Folding and layering is not a "More is better" process. She possibly meant "It has 200 layers" which is 8 folds.

During the final fight scene, the roof is flooded after the water tank is broken. However, when MacLeod and the Kurgan fall through the roof, water does not flood in to the room with them.

When Connor McLeod is having his duel with Bassett in 1783 one can clearly see that Bassett pushes his sword between McLeod's arm and chest in several killing attempts.

The Scotland scenes are supposedly set in the 1530s, but the clothing, weapons, and tactics used would be more fitting for the Dark Ages, some 600 years earlier. By the 16th century, most European armies consisted primarily of pikemen and musketeers.

During the very first shot of Eilean Donan Castle, as the camera elevates above the villagers, the sun reflects off of a car traveling along the A87. Visible very briefly, it emerges from behind the fir trees, in the top right hand side of the shot, as it follows the shoreline.

The MacLeod tartan they wear in the 16th century was in fact not adopted by the clan until 1910.

We see bagpipes with three drones in the 1500s; the long third drone was added after 1700.

In the scene where the Kurgan is fighting Ramirez he is using his modern, detachable high-tech sword. Even the fissure where the blade is divided can clearly be seen in several takes.

During the first fight between Connor and Fasil, when Connor grabs the metal pipe, Fasil swings and hits the pipe twice, the second time the connection sound is heard twice, when it clearly only connects once.

When Ramirez and the Kurgan are fighting in the tower, there are some scenes in which the Kurgan hits the walls with his sword and stones from the walls fall into the tower. In one of these, shortly before Heather starts to scream again, one can see a crew member behind the wall. He is probably the one who pushed the (prop-)stones inside. If you want to see it: the crew member is on the right side of the screen, a little above Ramirez.

Before the fight between Kurgan and Ramirez in the tower, when Heather and Ramirez are dining and Ramirez perceives Kurgan, he looks at the roof and the posed doves fly away. The flash of the explosion used to frighten them is clearly visible, and also the smoke moments later.

At 1h51m when Highlander is swinging between the roof and the floor, the security/hanging wire is visible at his right shoulder.

During the kidnap 'chicken run' scene when Kurgen is driving on the wrong side of the road into oncoming traffic the car accidentally collides with an oncoming vehicle as they both swerve in the same direction. The camera truck can be seen to slow and camera operator/director/crew member can be seen to rise up a little more and look back.

When the Kurgan is driving and listening to the radio talk about Connor, the close in camera shot is followed by a long shot where the front seat camera guy is visible.

The wrestling match shown is supposed to take place at Madison Square Garden. That promotion - the AWA based out of Minneapolis, MN never had an event take place in NYC. The WWF were the only promotion running shows at MSG.

Newspaper stand in "New York" displaying "Have You Seen This Man" headline is shot in front of the Sheraton Centre of Toronto.

Immortals are able to "feel" each other's presence. In the zoo however, MacLeod can't feel the Kurgan at the zoo, who is well within sight, so not far away. This is a problem in all versions except the US theatrical release version, since it does not contain the zoo scene (it was added to the director's cut for US release).

It seems rather odd (and convenient to the plot) that Brenda, a forensics technician, is a published metallurgy expert. Doing doctoral-level research in one field does not generally equate to getting a masters-level technician job in another, completely different field. She is incredibly young to have accomplished the former alone, and it is highly doubtful she could have achieved both at her age.

No rationale is given (or even suggested) for why Brenda would start searching birth certificates for Nash, nor for why she jumps to the conclusion that she must speak with the doctor who supposedly delivered him. At this point in the story, he's just a slightly suspicious character to her who showed up at a murder scene.

Conner claims to be born in 1518. His first battle is supposed to be (based on the war-cry of the priest) in 1536. However, if these details are correct, he looks at least a decade older than he should.

Ramirez tells Connor that if The Kurgan were to win The Prize that "mortal man would suffer an eternity of darkness." Not true. Once he received The Prize, The Kurgan would begin to age normally again, and the world would only suffer until he dies of old age. Of course, his statement could just be speculation since they don't know that he will begin to age again. Other option is that The Prize wasn't the same depending the winner and, unlike McLeod, Kurgan could keep his immortality, being still more powerful than before.

Ramirez calls himself the chief metallurgist to King Charles Fifth of Spain. Charles Fifth was not this king's official title in Spain, but his title as Holy Roman Emperor. He was King Carlos Primero, or Charles First, in Spain. Therefore, Charles Fifth was his title in Germany, that he had at the same time that his royal treatment in Spain. His historical full name is accurately Charles First of Spain and Fifth of Germany.

Brenda, a weapons expert, calls the sword a "samurai". Samurai refers to the Japanese swordsman. His weapon is called a "katana". (In mitigation, she is talking to non-experts and may well just be dumbing down for their sake.)

When the police are questioning Nash they refer to the sword as a broadsword. The sword (the Toledo Salamanca) was actually a rapier.

Sean Connery's character is supposed to be Egyptian yet he speaks with a thick Scottish accent throughout the movie. At least Christopher Lambert, despite being French, tried to give his character some credibility by speaking with a mock Scottish accent.

When Nash is in Brenda's apartment and they are having drinks, Brenda says; "Shall we have a toast?" and Nash agrees, but she is then seen drinking before either of them say anything else.