Purple Hibiscus, a novel that takes place in Nigeria, begins on Palm Sunday when the protagonist, a 15-year-old girl named Kambili Achike, describes an incident that begins the dissolution of her family. On that day, her older brother, Jaja, refuses to get communion at church. As a response, their father, a devout, wealthy Catholic named Eugene, throws a prayer book that breaks the mother's figures on the etagere.
Kambili then goes back in time to her family's history before this event, and she describes the emotional torture and control that her father exercises over her family. Kambili and her brother must, for example, earn perfect grades in school and follow their father's detailed wishes. Her mother tells Kambili that she is pregnant. Later, her father, annoyed that her mother does not get out of the car to greet a priest because she feels sick, beats his wife until she has a miscarriage. The newspaper Eugene runs becomes increasingly critical of the new government.
Ifeoma, Eugene's sister who is a university professor, convinces him to allow Jaja and Kambili to stay with her. She allows her three children far more freedom, and they practice a form of Catholicism that is combined with local Igbo beliefs. Though they are not rich, their way of life seems far preferable to that of Eugene in Kambili's eyes. While living with her aunt, Kambili comes to know a young local priest named Father Amadi, whom she feels attracted to. He practices a loving kind of Catholicism through which he helps local children. Eventually, Papa-Nnukwu, Ifeoma and Eugene's father, comes to live with Ifeoma, but he dies while he is visiting. Eugene becomes upset that his children were living with his father because he considers his father to be a heathen, as the father does not practice Catholicism. After a brief visit home, during which Eugene beats Kambili, they return to Ifeoma's house, although their aunt is engaged in controversy against the new administration at her university. She and her children eventually leave for America.
The end of the novel returns to the fateful Palm Sunday on which Jaja refuses to take confession. Their father dies, and the mother confesses to her children that she poisoned him. Jaja takes the blame for the crime, and he goes to prison. The book concludes three years later, when Jaja is about to be released from prison.