There is a reference to a "Dr. Koji" by the psychiatrist. This is a nod to the original writer of the Ring books, Kôji Suzuki.
When Rachel takes the pills and puts them on the sandwich for Aidan, she crushes the pills into a powder. The medicine bottle has a label that can be seen with the name Tony Bonaventura, who is the property master for the film.
Commercials director Noam Murro was set to direct, but dropped out of the project citing creative differences with Dreamworks Studio.
Richard Kelly was offered the chance to direct, but turned it down.
Copies of the "Cursed Tape" were dropped in public places as a form of promotion. After about five minutes of footage, the viewer is directed to the movie's website.
According to the production notes, there were bizarre incidents on set of life reflecting art. On the seventh day, the production office was discovered to have flooded overnight, the result of a burst water pipe. Water is a strong theme in the film. In response, director 'Hideo Nakata' requested a Japanese purification ceremony be carried out by a Shinto minister, but the strange incidents continued. While on location, a swarm of thousands of bees descended on the prop truck, prompting the immediate evacuation of the department, before the bees left as quick as they arrived. For no apparent reason, a five-gallon water jug burst open in the production office kitchen, one again flooding the same room that had flooded only weeks earlier. One morning on the Universal lot, a set costumer stepped out of the parking garage to discover an antlered buck charging across the asphalt in her direction. Though deer are a regular occurrence in the hills, the similarity to the deer attack in the film is uncanny.
When Naomi Watts and her son go to the outdoor Astoria Antique Fair Swap Meet, Watts picks through a bunch of used VHS videos at a vendor's stand - and all the movies are Dreamworks titles, such as Old School (2003), and Win a Date with Tad Hamilton! (2004).
During the shooting of a carnival scene, locals mistook the set for an actual carnival and wandered in. They were included as extras in the film.
Even with three artists, Samara's make-up took over five hours to complete.
In the scene following the tape burning, when Rachel gets Aiden out of bed after finding him "soaked and freezing" after having a nightmare we can see that the wet part of his bed is ring-shaped.