Donal Logue reinjured his jaw in the scene where he is struggling with N'Bushe Wright in the hospital. He had originally broken his jaw in a motorcycle accident years before.
A great many handheld shots were accomplished with a special anamorphic-lens camera that also had single-unit sound - the only one of its kind in the world.
In the scene where Blade is chased to the subway, and the subway train is passing by, all the passengers are cardboard cutouts with the special FX man among them.
The true name of the Blade character is Eric Brooke. ("Eric" is mentioned once in the film, and Blade's mother's driver's license says Vanessa Brooks of Bradenton, Florida).
Stan Lee originally had a cameo that was ultimately cut from the film. He played one of the cops that come in to the blood club during the aftermath and discover Quinn's body on fire.
When David S. Goyer first pitched the idea of doing a Blade movie, the executives of New Line felt there were only three actors who could possible do the role: Wesley Snipes, Denzel Washington and Laurence Fishburne, but in Goyer's mind, Snipes was always the perfect choice for the character of Blade.
The scene where Karen and Deacon are talking about the cure for vampirism initially ran a bit longer and answered the question of how the vampires would feed if everybody was turned into a vampire. They would keep some humans alive in giant blood bags to harvest them. The bags can still be seen in a doorway during the scene, and later played an integral part of the plot in Blade: Trinity
Wesley Snipes became attached to the project because he was in discussions with Marvel Comics to be Black Panther, a project that is still pending as of 2005.
Kris Kristofferson's character Whistler was created for Blade's cameo on the Spider-Man cartoon show. He was liked so much by Marvel CEOs that he was adopted into the Marvel universe.
In the film, Whistler can read the ancient Vampire Language. We see this when he translates the piece of paper taken by Blade from the archive room. However in the script, Whistler cannot understand the language and Blade goes to a Voodoo priestess to get a translation.
David S. Goyer explained in the DVD commentary that when Karen Jensen wakes up at Blade's hideout after her attack and rescue by Blade, the script had her discover a jar with a vampire baby in it. The baby would be alive and used by Blade and Whistler as a guinea pig for testing out weapons to fight vampires. The studio however found the concept to be disturbing and refused to allow it.
The trivia items below may give away important plot points.
The first cut of the film had a disastrous test screening with audiences, and heavy edits and re-shoots were implemented which delayed the release date more than half a year. The most significant change was the addition of the final sword fight between Blade and Deacon Frost, which did not exist in the original version of the movie.
In the ending as it was originally planned, Frost turned into La Magra and became a large swirling mass of blood instead of keeping his form. This was scrapped because they couldn't get the special effects to look right. It can be seen as a special feature on the DVD.
Stephen Norrington:
During the chase with officer Krieger, the vampire on the side of the road biting the girl's neck. In the alternate ending on the DVD, the blue figure in the black coat on the roof is Norrington again, as an unnamed vampire.