The story revolves around investment banker Patrick Bateman who is also the narrator. He describes his daily activities, including going to nightclubs and taking drugs, and also his relationship with Evelyn, his mother, and brother. He often makes random references to music artists during his retelling of his story.
Throughout the novel, it becomes clear that Bateman may be mentally unstable and therefore this makes him an unreliable narrator. Bateman spends his days as an investment banker but at night, he transforms into a killer. He kills his co-worker, Paul, and decides to continue his killing spree in his apartment. As he carries out more murders, his methods change, becoming more torturous, even including rape and cannibalism. He often reveals his murderous activities to his coworkers, in casual conversations, but they don’t take him seriously and think he is joking.
Later, Bateman begins to experience hallucinations and these result in him killing many people in public. The SWAT team arrives and this urges Bateman to run and call his attorney to confess the crimes he has committed.
He then visits Pal’s apartment, where he left dead bodies. However, when he arrives it is completely clean. The real estate agent questions why he is present and he claims he saw an ad for the place to rent. He then leaves.
His attorney then calls him back and laughs off the murders, saying that it is impossible that he killed those people because he is too much of a coward and also he could not have committed the crime because he was having dinner with him twice that week when it occurred.
The books wraps up with Bateman back in the nightclub talking about trivial matters with friends again.