- This episode was awarded the 2003 Hugo Award for Best Dramatic Presentation, Short Form .
- Neither Emma Caulfield nor Nicholas Brendon appear in this episode. This is the only episode Brendon, and the character of Xander , does not appear in throughout the entire series. James Marsters appears but does not speak.
- Amber Benson was initially going to appear as Tara, taunting Willow instead of Cassie, but she turned it down on the grounds that she thought having Tara as a villain would ruin her character. According to the commentary for this episode on the DVD, the writers said that Amber Benson simply wasn't available.
- Other storylines considered were for Eric Balfour, who played Jesse in the pilot episode, to have conversed with Xander; and, according to Drew Goddard on the "Selfless" DVD commentary, for Kali Rocha (Halfrek) to return and haunt Anya, but she was unavailable.
- Buffy learns that Scott Hope , her high school boyfriend in season three, came out as being gay in college. This may have been a nod to the fact that the actor that played Hope, Fab Fillippo had gone onto have a major role in the Showtime television series Queer as Folk as an openly gay gifted violinist at a private University.
- Jonathan M. Woodward , who plays Holden Webster, also appeared in every Joss Whedon series: as Knox in the fifth season of Angel , and as Tracey in the Firefly episode " The Message ". All three of these characters died violently.
- Holden Webster pronounces "nemeses" correctly and Buffy replies "Is that how you say that?" This is an allusion to the Season 6 Episode "Gone" when both Warren and Buffy have trouble with the word.
- On the DVD commentary for the show, Jane Espenson revealed that the image of Joyce was actually The First. It's explained that The First can simply be in more places than once, something that could already be inferred with Warren being visible to Andrew at the same time as Cassie talks to Willow.
- Espenson claims to have given her first production note that made it to air: the monster appearing to strangle Joyce was actually the Gnarl costume from "Same Time, Same Place" turned inside out and spray-painted black.