|Genre||Young adult novel|
|LC Classification||PZ7.B6265 De|
Deenie chronicles the life of 13-year-old Wilmadeene "Deenie" Fenner, whose mother is determined to have her become a model. At the same time, Deenie's 16-year-old sister, Helen, who is academically proficient, is being pushed by their mother to keep her grades up so that she can eventually become a doctor or a lawyer. One day, Deenie is diagnosed with scoliosis, and is prescribed a body brace to wear for the next four years. At the same time, Helen has fallen in love with Joey, a charming and romantic young gentleman who works for the family business, a gas station. Mrs. Fenner, upset that her plans for her daughters are coming undone, has Joey fired and still exhorts Deenie to pursue a modeling career once she stops wearing the back brace. Though fearful that Helen will hate her because Mrs. Fenner said that Joey was let go because of the family's doctors' bills, Deenie is astonished to learn that Helen refuses to blame her for Joey's departure, and the sisters close ranks.
Though initially upset at having to wear the body brace, Deenie eventually resigns herself to her fate. She finds herself at peace with the idea of not becoming a model, and, inspired by her experience, begins to ponder a future career as an orthopedist, concluding that she never really wanted to be a model herself. The book concludes with Deenie asking her father for permission to not wear the brace to a party, and though her mom is surprisingly relaxed about it, her father, who until now was rather mute about everything, firmly says 'no', rightfully pointing out that she'd want to not wear it for every special occasion if he gave in. In defiance, she brings a bag with clothes that fit her without the brace with the intention to change once she gets to the party, but once there, Deenie changes her mind and leaves the brace on.
Other story arcs include Deenie's friendship with a girl whose eczema alienates her, and Deenie's anxiety over whether her crush will still like her in spite of her back brace.
This book, like many others written by Blume, has been banned in schools for themes deemed inappropriate for adolescents; in this case, talk about masturbation and sexuality. Deenie is on the American Library Association list of the 100 Most Frequently Challenged Books of 1990–2000 at forty-sixth. 
The passages that are most frequently cited as reasons for removing the book from libraries are: "[That week] I touched my special place practically every night. It was the only way I could fall asleep and besides, it felt good" [p. 79 in the 2005 Laurel-Leaf edition] and "Usually I take showers and get in and out as fast as possible. But the hot water [in the bathtub] was very relaxing and soon I began to enjoy it. I reached down and touched my special place with the washcloth. I rubbed and rubbed until I got that good feeling" [p. 129].
These, along with a discussion about menstruation and masturbation [p. 79-82] led by a gym teacher, are the core of the objections to the novel. The book is otherwise usually described as insightful and accurate in portraying a young girl dealing with her diagnosis of scoliosis, as well as coming of age. Another important topic is of a parent or parents "pigeonholing" their kids into a profession they want them to go into, as was the case of Deenie's mother to both her and Helen, with the excuse that she "just wanted better" for them. In her words, "Is that so wrong?"
- Deenie Fenner — The main character who has scoliosis
- "Aunt" Rae — Deenie's mother's best friend
- Janet — One of Deenie's best friends
- Midge — Another of Deenie's best friends
- Helen — Deenie's sister
- Buddy Brader — A boy Deenie has a crush on.
- Steve — A boy Janet has a crush on.
- Harvey — The President of the School and also Janet's love interest
- Thelma — Deenie's mother.
- Frank — Deenie's father.
- Joe — Works at the garage with Deenie's father. Has a brief love interlude with Helen until he is fired.
- Barbara — a friend of Deenie's who suffers from eczema.
- Susan — an obnoxious classmate of Deenie's who always copies everything she does
- Eileen Rappoport — Deenie's gym teacher
- ALA | 100 Most Frequently Challenged Books of 1990–2000 at www.ala.org