Greg Sestero stated that when he was writing the book, Tommy Wiseau said that only two actors could play him in the adaptation: James Franco or Johnny Depp. Wiseau, who claims to have once lived in New Orleans, was a fan of Franco's performance in the film Sonny, O Amante (2002).
In real life, Greg and Tommy did not move to Los Angeles at the same time. Tommy offered his LA apartment to Greg, for a nominal rent for several months (though Greg stated none of the rent checks he sent to Tommy were deposited), while Tommy came and went from San Francisco at random. Once Greg had booked some small gigs, Tommy suddenly moved in full time to the LA apartment, cashed all of Greg's checks at once overdrawing his account, and set up the divider in the living room as seen in this film.
In actuality, Greg Sestero had no interest in acting in The Room (2003) and originally only intended to serve as the film's line producer, and Tommy Wiseau had cast a different actor to play Mark. The night before filming began, Wiseau spontaneously decided that he wanted Sestero to play the role. Sestero reluctantly accepted after Wiseau offered him a substantial pay raise and a new car. Rather than telling the original actor that he had been replaced, Wiseau had him come to set and perform his scenes for weeks, but instructed the camera crew not to roll any film.
Seth Rogen and Jonah Hill were early devoted fans of the film. At one point, Hill saw Tommy Wiseau at a grocery store in Los Angeles and was so starstruck that he secretly took a photo of Wiseau shopping that he immediately sent to Rogen.
In almost every interview for The Disaster Artist, James Franco mentions that Tommy Wiseau approves of "99.9%" of the film; his only objections were the lighting of the first scene, which Franco believes was because Tommy was wearing sunglasses when watching the scene, and also for the poor way James threw the football.