Aron Ralston filmed a daily video diary while he was stuck in the canyon; parts of the video diary were shown on a televised special about his entrapment, however most of the footage has only been shown to close friends and family and is kept in a bank vault for safety. Before shooting began both James Franco and director Danny Boyle were allowed to view the footage in order to accurately portray the events in the movie.
The camcorder used by James Franco in the film was the actual one Aron Ralston used when he was trapped in Blue John Canyon.
Terry Mercer, who portrays the helicopter pilot that rescues James Franco as Aron Ralston in the film, was the actual helicopter pilot that rescued Aron Ralston.
Since Ralston did not tell anyone that he was going hiking, no one knew that he was missing or even where to look for him. However, this lesson seems to have been lost on readers of his biography and audiences of the subsequent movie. One of them, 64 year old Amos Wayne Richards ventured to the same spot Ralston did also without telling anyone. While climbing down a 70-foot-deep ravine, Richards slipped and fell the last 10 feet to the bottom. During the fall, he dislocated his shoulder, bumped his head on a rock, and broke his leg. It took Richards four days to crawl out of the ravine and by the time the park rangers found him he had no remaining water. In the end, it was the hysteria of 127 Hours fans that saved Richards. The park rangers at Blue John Canyon knew where to look for Richards because of the influx of hiking enthusiasts to the canyon since 127 Hours was released. In fact, since 2005 (Ralston's biography came out in 2004), more than two dozen rescues have been performed in that same area - between 1998 and Ralston's incident there were none.
For the moment when Aron falls down the canyon and gets his arm stuck under the rock, Danny Boyle filmed James Franco for 20 minutes straight going through all kinds of emotions. He then cut the material the way it ended up in the movie.