Flip-Flop of God: Paul Verhoeven on whether the events of the film were real or all in Quaid's mind. In the commentary, Schwarzenegger leans more to it actually happening, whereas Verhoeven leans more towards it being the ego-trip.
Saved from Development Hell: Scripts had been kicking around Hollywood so long people thought the project was jinxed. Dino De Laurentiis owned the film rights and had tried to get the project off the ground twice in Rome and Australia. Originally it was less violent and more about the fantasy of taking a trip to Mars. Schwarzenegger was annoyed that De Laurentiis didn't offer it to him because he really wanted the part. Patrick Swayze and Richard Dreyfuss had been in the running to play Quaid but De Laurentiis ran into money troubles (not for the first time), so Schwarzenegger tried to persuade Carolco to bankroll the film and they bought it off him.
Technology Marches On: Although the film is set in 2084, an advertisement is seen for Fuji Film despite the fact that by the early 2000s, analog photography has been made all-but-obsolete by digital photography.
Troubled Production: The Mexico City shoot was considered a nightmare for most of the cast and crew. Many cast and crew members got sick at one point from contaminated water (the only major members of the production who didn't get sick were Arnold Schwarzenegger, who had remembered being sick during the Mexico shoot of Predator and took special precautions, and producer Ronald Shusett, who would give himself B12 shots each day to avoid illness) and the air was so polluted that Schwarzenegger recalled having trouble breathing on most days.
David Cronenberg was set to direct and even wrote a few drafts of the script before Paul Verhoeven took over. Cronenberg stated that he wanted to cast William Hurt as the lead, and was displeased by the producers' decision to reimagine the lead for an action star such as Schwarzenegger.
Over 40 drafts of the script had already been written when Paul Verhoeven agreed to read the screenplay. Some of them depicted Quaid as a mild-mannered accountant (instead of a construction worker). Most scripts had a similar first half (Quaid visits Rekall and starts having altered memories), but they all varied widely in the ending. One of them even had Quaid discover that he was really an alien in human disguise.
Cynthia Rothrock was considered for Lori. According to Rothrock, she found out years later that she didn't receive the part predominantly because some of her would-be costars were concerned by the prospect of being outshone by a female martial artist.