In this paper I analyse the narrative technique of unreliable narration in Bret Easton Ellis’ American Psycho (1991). Critics have been split about the reliability of Patrick Bateman, the novel’s gruesome narrator-protagonist. Using a new model for the detection of unreliable narration, I show that textual signs indicate that Patrick Bateman can be interpreted as an unreliable narrator. This paper reconciles two critical debates: (1) the aforementioned debate surrounding American Psycho, and (2) the debate surrounding the concept of unreliable narration itself. I show that my new model provides a solution to the weaknesses which have been identified in the rhetorical and cognitive models previously used to detect unreliable narration. Specifically, this new model reconciles the problematic reliance on the implied author in the rhetorical model, and the inconsistency of textual signs which is a weakness of the cognitive approach. In conclusion, I demonstrate how the technique of unreliable narration has undergone a paradigm shift towards a greater historical and cultural interaction with historical and cultural contexts. The example of American Psycho will be used to demonstrate the interaction between the narrative form of unreliable narration and thematic content.