The Butcher Boy by Patrick McCabe is a novel that explores the consequences or effects of abnormal childhood development owing to a dysfunctional family. The other major theme of the story is the complex dynamics in a friendship—particularly the emotional intricacies within a symbiotic relationship.

Within these themes, McCabe examines the mechanisms of attachment and detachment found in relationships. The death of the protagonist's parents( with the mother committing suicide) and the abandonment of his best friend trigger the development of his psychopathic tendencies.

In essence, the novel is about the human conditions people face in a world that is unforgiving, and how humans relate to the world around them. Set in rural Ireland, the story is reminiscent of traditional Irish folklore and ballads which emphasize the dark elements of the human psyche.