Continuity mistake: After Blade shot the human, he walks up to where the human is lying on the ground. The male body lies to the left of the yellow line on the road. When Danica is looking at what she has recorded, on her computer's monitor, the body shown on the screen is now lying on the yellow line. (00:11:50)
Continuity mistake: Shortly after the Interrogation scene (when Danica, Asher, and Jarko walk in to meet Blade) Asher Talos begins to unlock Blade's hand restraints. Not only is his head up, then right next to Blade's face in the very next shot, but he also has a cigarette in his mouth when he begins. In the next shot the cigarette is gone, and does not reappear.
Continuity mistake: In the interrogation room scene where Hannibal King rescues Blade, when Blade kicks Triple H through the wall, Blade says " Go " to Hannibal he grabs his gun, if you slow it down, the bag with the syringes has gone in one shot and reappeared on the table in another. (00:35:25)
Audio problem: When the chief of police arrives at the blood farm he is surprised by Blade and Abigail. He quickly reaches inside his jacket to draw his pistol but Abigail draws her revolver much faster. As she draws there is the unmistakable metallic sound of a revolver being cocked, but when she extends the revolver out in front of her to cover the chief the hammer is down, not cocked. The revolver could be seen in the holster with the hammer down, so she could not have been manually decocking it to make that sound.
Plot hole: It is said that Drake has been sleeping for 4,000 years. But Drake specifically mentions that he witnessed Christ being crucified, which happened around 2,000 years ago. This harkens back to a plot line where Drake had only been sleeping since the turn of the century, abandoned in favor of the one shown in the movie.
Continuity mistake: When Danica and the others are inside the pyramid, Danica is holding her blue lantern at chest height but when the camera cuts to an overhead shot of the sinking sand, the lantern is being held down by the legs, at the left of the screen. (The blue light reflection is on the knee.) (00:03:15)
Deliberate mistake: When Blade Abigail and Hannibal go to visit Dr Vance, Drake grabs Hannibal they move to a window, if you look behind them, the window is closed, then when Drake stabs Hannibal the window is open, then after drake goes out the window, you hear the window smash, even though he went out an open window. (00:56:15)
Continuity mistake: When Blade goes back to his base where Whistler is, and they begin to talk over the night's mess up, Blade pulls out the dagger Whistler made. In the first shot he is holding the dagger by its handle, then in a shot from the back he is holding it at the blade, and next shot back at the handle again. (00:13:10)