The original script by Richard Matheson called for Carl Kolchak to be dressed in Bermuda shorts and wearing an Aloha shirt. Actor Darren McGavin said, "That doesn't sound like anyone I know," and elected to use a different wardrobe. While reading up on the character, McGavin noted that Kolchak had been fired from a New York newspaper years before, and thought, "That's it! He hasn't bought a new suit since!" So, Kolchak appeared in a circa 1950s suit.
While filming in Las Vegas, producer Dan Curtis was amazed at how oblivious the casino gamblers were to any events going on around them other than gambling. So as a joke one day, actor Barry Atwater (Janos Skorzeny) was asked to walk through the Sahara's casino in full costume and makeup to see if anyone noticed him. He did this for over 40 minutes, and didn't even get a second glance.
When Kolchak's exploring Skorzeny's house, he opens up a refrigerator and finds one of the bottles of blood stolen from the hospital. The bottle is labeled, "Richards, Benjamin". This appears to be a leftover prop from The Immortal: Pilot (1969), a TV-movie (later a series, The Immortal (1969)) about a man named Ben Richards whose blood makes him immune to aging and disease.
Actor Barry Atwater was given red contact lenses for his role as vampire Janos Skorzeny. After wearing them for long periods his eyes became very sensitive - as a result, he did not need the contact lenses to make his eyes look red in later scenes.
A planned third installment in the franchise, 'The Night Killers', was scripted but ABC opted to develop the TV series instead of continuing the films. The plot had Tony Vincenzo hiring Kolchak to work for him in Honolulu. While there, Kolchak discovers a cover-up involving UFOs, a nuclear power plant and important people being murdered and replaced by androids.
The music from the 1970 movie House of Dark Shadows was used towards the end of the TV movie Night Stalker. It is particularly noteworthy towards the end of the movie as Kolchak and Bernie Jenks (Ralph Meeker) are fighting Janos Skorzeny (Barry Atwater) in the vampire's house.
The vampire, Janos Skorzeny, was played by Barry Atwater. One of the first series that Fox Network broadcast was called "Werewolf." The predator that turned that show's main character into a werewolf was played by Chuck Connors and was also named Janos Skorzeny, an homage to the character in "The Night Stalker." This was a recurring character, and in an interview Chuck Connors said that it was one of his favorite characters and thoroughly enjoyed playing it.
The werewolf Janos Skorzini was played by Barry Atwater. One of the first series that Fox Network had was called Werewolf. The vampire that turned the main character was played by Chuck Connors was named Janos Skorzini as an homage to the character in The Night Stalker. This was a recurring character and in an interview later, Chuck Connors said that this was one of his favorite characters that he had ever played and he thoroughly enjoyed doing it.