The book chronicles both the life of Oscar De León, an overweight Dominican boy growing up in Paterson, New Jersey who is obsessed with science fiction and fantasy novels and with falling in love, as well as the curse that has plagued his family for generations.
The middle sections of the novel center on the lives of Oscar's runaway sister, Lola; his mother, Hypatia Belicia Cabral; and his grandfather, Abelard. Rife with footnotes, science fiction and fantasy references, comic book analogies, and various Spanish dialects, the novel is also a meditation on story-telling, the Dominican diaspora and identity, masculinity, and oppression.
Most of the story is told by an apparently omniscient narrator who is eventually revealed to be Yunior de Las Casas, a college roommate of Oscar's who dated Lola. Yunior also appears in many of Diaz's short stories and is often seen as an alter ego of the author.