During the filming of this episode Jared Padalecki (Sam) injured his hand when he fell badly during a stunt. He thought it was merely sprained and went straight into filming the next episode (2.04 Children Shouldn't Play with Dead Things (2006) without having it checked. But it got more and more painful and finally he went to the doctor and discovered that his hand was, in fact, broken. Because he had already begun filming, he couldn't bandage the hand until filming for that episode was finished. The writers ended up writing in an accident for Sam and his line "I think she broke my hand" to explain the fact that for the following few episodes he would be wearing a cast.
Amber Benson who plays the vampire Lenore in this episode has a recurring role as the witch Tara in the perhaps most famous show revolving around vampires - Buffy the Vampire Slayer (1997).
First episode where Sam began parting his hair down the middle, the hairstyle he'd keep the rest of the series.
First episode with mention of the Winchester brothers notoriety.
Amber Benson would return to the character of Lenore, the non-human-blood-drinking vampire four years later in the Season 6 episode, Mommy Dearest (2011).