The United States edition of Good Omens had numerous alterations to the text. The most significant alteration to the main text is the addition of an extra 700-word section just before the end, dealing with what happened to the character of Warlock, the American diplomat's son, who was swapped with Adam. The American edition also adds numerous footnotes not found in British editions.
The Dutch translation of Good Omens contains a preface by the translator wherein he asserts that no extra footnotes were added to clarify matters that might be unclear to a modern audience—annotated with footnotes explaining omen and Crowley.
In the French version, some characters were given French-sounding names. Agnes Nutter became Agnès Barge (barge is French for nutter), Anathema Device became Anathème Bidule (Bidule being French for Device). Crowley became Rampa (as 'Crawly' became 'Crowley', 'Rampant' became 'Rampa'), after the infamous author of The Third Eye, T. L. Rampa. The French publisher of Good Omens (J'ai Lu) was also the French publisher of the T. L. Rampa books.
668—The Neighbour of the Beast was slated as the title for a sequel to Good Omens, but after Neil Gaiman moved to the United States, Terry Pratchett expressed doubt that a sequel would be written. Gaiman later affirmed this in one of his essays, titled Terry Pratchett: An Appreciation.
A film, directed by Terry Gilliam, was planned. As of 2002 Gilliam still hoped to make the film with its already completed script, but by 2006 it seemed to have come to nothing. Funding was slow to appear and Gilliam moved on to other projects. There was a rumour that Johnny Depp was originally cast as Crowley and Robin Williams as Aziraphale. However Gaiman has said on his website, "Well, Robin's worked with Terry Gilliam before as well, of course, most famously in The Fisher King. But I have no idea about Good Omens casting (except for Shadwell. Terry told me who he wanted to play Shadwell. I immediately forgot the man's name, although I can assure you that it wasn't Robin Williams)." According to an interview in May 2006 at The Guardian 's Hay Festival, Gilliam is apparently still hoping to go ahead with the film.
Gaiman confirmed in a podcast interview with Empire in 2013 that the majority of the funding for the film was in place in 2002, but the project couldn't attract the initial funding to begin production.
Even in 2008, Gilliam was still hopeful about the project. Neil Gaiman's Stardust and Beowulf were successful as films in 2007, which has given the Good Omens adaptation a better chance to get picked up. A Gilliam quote from an Empire interview: "And I thought with Neil, with Stardust and with Beowulf and there’s another one – an animated film, a Henry Selick thing he's written Coraline, I was thinking he's really hot now, so maybe there's a chance. I mean it's such a wonderful book. And I think our script is pretty good, too. We did quite a few changes. We weren’t as respectful as we ought to have been. But Neil's happy with it!"
The history of this project and similar experiences with Gaiman's various other works (including The Sandman series) have led to his cynical view of the Hollywood process, a view which occasionally surfaces in his weblog and in some of his short fiction. Pratchett shared a similar opinion, and was quoted as saying, "The difference between me and Neil in our attitude to movie projects is that he doesn't believe they're going to happen until he's sitting in his seat eating popcorn, and I don't believe they're going to happen."
Pratchett had had many of the same issues with Hollywood 'suits', but he, too, would love to see the film made.
In August 2012, Rhianna Pratchett, Terry Pratchett's daughter, announced an establishment of a new production company, Narrativia, which will, among other projects, produce a TV film based on Good Omens.
In March 2013, Cult Classic Theatre in Glasgow, Scotland, performed Amy Hoff's adaptation of Good Omens with the permission of Pratchett and Gaiman.