- Don't Forget Me!: Danielle Warner and her brother, Peter, move into a house where the basement is haunted by the ghosts of children who have been forgotten by their friends and families — and lure living children in by making their friends and families forget about them.
- Locker 13: Superstitious Luke Green gets assigned Locker #13 on his first day of school and tries to quell the bad luck that goes along with it by finding a good-luck charm. But the good-luck charm has a twisted secret of its own.
- My Name is Evil: A carnival fortuneteller accuses Maggie of being evil. Maggie brushes it off as a joke — until accidents occur in school and all signs point to Maggie as a suspect.
- Liar Liar: Years of lying suddenly catch up with Ross when he finds himself in a parallel world where an evil twin tells him that he will die in two days.
- Dear Diary, I'm Dead: Alex Smith discovers a diary in his room that predicts the future, including his death.
- They Call Me Creature: Laura must find out why the animals she cares for are attacking her and what her father is doing in the backyard shed.
- The Howler: Self-proclaimed electronics geek Spencer Turner buys a machine called "The Howler" that lets humans communicate with the dead...and summons a ghost family who wants to kill his friends and family.
- Shadow Girl: A bored girl named Selena discovers that she is really a superheroine named Shadow Girl, and, like all superheroes, has an arch-enemy who wants her dead.
- Camp Nowhere: At summer camp, Russell rows over Forbidden Falls — and finds himself in a summer camp haunted by the ghost of an evil Indian spirit.
- Full Moon Halloween: It's a frightful Halloween night as a teacher gets four of his students and try to discover that one of them may be a werewolf.
- Scare School: Sam is haunted by an imp at his new school who preys on new students.
- Visitors: UFO enthusiast Ben Shipley discovers that aliens are covertly invading Earth.
In mid-2001, a spin-off trilogy series to The Nightmare Room was released, under the name The Nightmare Room Thrillogy. The books had an overarching story arc, which followed the character April Powers who is invited to a game show that takes place on an island haunted by an evil witch.
- Fear Games: Twelve kids with special abilities have been selected to take part in a reality show called Life Games, set on an island haunted by a psychotic witch.
- What Scares You the Most?: April (one of the contestants) is stranded on the island and must fight her biggest fears in order to escape.
- No Survivors: After her escape in What Scares You the Most?, April must return to the haunted island in order to rid it of the witch's spirits.
All 12 books in The Nightmare Room series have been released digitally with their original covers and designs. They are available for download on services such as iTunes and Scribd. The first five books in the series feature bonus material sections in the back of the book, which were named Go Deeper into This Nightmare. These include fictional interviews with characters from Nightmare Room books, urban myths and legends relating to Nightmare Room books. These materials were originally only available on The Nightmare Room website.
In the early 2000s, the first six books in The Nightmare Room series were released in a digital omnibus named The Nightmare Room: an E-Omnibus. The book also contained the short story Dead of Night which was written by R. L. Stine and previously only available on The Nightmare Room's official website. The E-Omnibus is currently unavailable for download.
- In an interview with Bustle, R. L. Stine described The Nightmare Room series as "a total bomb," but also commented that he liked the books and wondered why they weren't as popular as his Goosebumps series.
- When The Nightmare Room television series was released in mid-2001, the design of the series' logo was changed to match that of the TV series. The books that featured the new logo were #10: Full Moon Halloween, #11: Scare School and #12: Visitors.