Katherine Lewis is a dentist who comes from a long line of families in Dentistry including her late father, she likes her job, but is dissatisfied with her social life. She is afraid of loving anyone in case she loses them as she lost her father.
One day, Katherine is walking to the bank to deposit a few cheques during a rift in her schedule and she sees her best friend Mindy across the street. She is accidentally knocked onto the road by a bike messenger. She is unable to move out of the way in time and gets hit by an uncoming car that kills her.
She awakens and finds herself in an area called Limbo, a place referred to being between Heaven and Hell. The receptionist reveals to her that she has died and that she must find her case worker for further instruction. A strict supervisor named Rogers comes along and reveals that when someone dies, if he or she had not performed good deeds on Earth, then they must perform community service as mythical being in order to go to Heaven by heading up the Stairway to Heaven. If they fail, they go to Hell through the Hellevator.
After looking through the book of former dentists' choices of community service options, she decides on "Bicuspid retrieval," and signs her contract, it is not until too late that she finds out that she has to be the Tooth Fairy. She is then trained by a worker named Raul on how to perform her service. When Katherine asks about the previous one, Rogers states that she was fired.
Rogers shows Katherine to her office, which contains a non-working, television that shows her children who lose their teeth, and a vintage typewriter that automatically dictates the names and locations of said children.
On her first night on the job, Katherine visits a boy named Bobby Jameson. As it turns out, children who have at least one baby tooth can see her, while those who have lost all of theirs can't, as the loss of baby teeth represents the loss of innocence required to see paranormal beings. He seems to be very angry and is rude to her; she changes his tooth into a silver coin with her wand and leaves, while he is somewhat convinced that he is dreaming. The next day when he is at school, a bully named Jeff punches him and knocks another one of his teeth out. Katherine comes to visit him again that night and discovers that his mother has died of cancer and his father is always so busy at work to spend time with him. She decides to help him and the other children at his school with their problems, which lands her in trouble with the higher-ups in Limbo, as revealing herself to living humans is against the rules.
When she is found out, she stands before the Council of Judges (all of whom are named Joe) who tell her that her access to Heaven has been denied due to an overflowing tooth bank, 47% retrieval and an all time high approval rating, but she is let off with a warning. She feels that the children's needs are greater than hers and asks for Raoul's help in making her visible to the parents and the school principal so that she can prove that she is real and that Bobby is not insane.
Katherine succeeds in becoming visible to the adults and is found out yet again by Rogers, who comes with Raoul to drag her back to Limbo. Once there, Rogers has her sent to the Hellavator. She begins her descent down it in a boiling rain, but suddenly finds herself back on Earth. She learns from Raul that not only was she dreaming, but has been given a second chance of life too. She figures that her father used his connections in Limbo to get her a second chance as she learned her lesson. She then notices Rogers as a traffic warden who says that she will be watching her.
Katherine returns to her job with a newfound love of life. She finds Bobby, a new patient, waiting for his appointment with her; she explains what happened and goes on to live her life fully. After she removes his last baby tooth, though, all of his memories of her as the Tooth Fairy are lost, and she's saddened that he no longer knows her. His father recognizes her from when she turned visible, and she asks them to go to a baseball game with her and they accept, implying a future relationship with Mr. Jameson.
- Kirstie Alley - Katherine Lewis/Tooth Fairy
- Dale Midkiff - Thomas Jameson
- Ross Malinger - Bobby Jameson
- Daryl Mitchell – Raul
- Kathryn Zaremba – Carrie
- Marcus Toji – Trevor
- Melanie Mayron – Mindy
- Lynn Redgrave – Rogers
- Eileen Brennan – Joe #1
- Kimberly Scott – Gwen
- John P. Connolly – Dr. Green
- Catlin Adams – Carrie's Mom
- Patrick Kerr – Mr. Wood
- Jake Richardson – Jeff
- Zack Duhame – Kent
- Arjay Smith – Phil
- Joel Swetow – Joe #2
- Kaley Cuoco – Lori
- Augie Amarino – Man in Hellavator
- Stephen Spacek – Bike Messenger
- Thomas Crawford – Cupid
- Candy Trabuco – Photographer
- Gregory Hinton – Tiny
- Lindze Letherman – Molly
- Helen Slater – Katherine's Mom
- Lewis Smith – Young Hot Guy
- Yeardley Smith – Gatekeeper
- Joel Brooks – Principal Norris
- Keaton Savage – Little Boy (uncredited)