The game started development sometime during 1998, being developed for at least 2 years, which during the next development year, the third game was released.
Originally, Jill was intended as main lead protagonist before Claire, this replacement was due to Hideki Kamiya altering the ending of the second game forcing scenario writer Noboru Sugimura to replace Claire with Jill. Jill later became main lead in the third game.
During the early development stages of the game, Alfred and Alexia Ashford were named Hilbert and Hilda Krueger, respectively.
Included with certain versions of CODE:Veronica X is an unlockable documentary titled Wesker's Report. This is a short feature narrated by Wesker, which brought players up to speed on the events in the series thus far.
This game's events on Rockfort Island are revisited in a canon, arcade-style fashion in Resident Evil Survivor 2 CODE:Veronica; the events in this installments are nightmares Claire has after Rockfort Island
Resident Evil CODE:Veronica had a beta version that featured a different outfit for Claire.
In the HD re-release of Resident Evil CODE:Veronica X, Claire Redfield has a shadow when she holds her lighter.
Resident Evil CODE:Veronica X has been confirmed as the third-rarest game to ever be released in America on the GameCube.
The Chinese company SkyWalker Comics wrote a manhua adaptation of this game. In addition to a lot of hand-to-hand combat (Chris, Claire, and Steve each take out monsters using unarmed attacks) and some rather ridiculous shots (Claire kills multiple zombies with a single bullet), Chris is portrayed as being left-handed. The manhua also features a "flash back" of the first game, to recount Chris' last encounter with Wesker. This manhua was soon after localized by WildStorm comics.