The novel is split up into seven sections: the first six contain multiple chapters of varying length and differing focus. The novel's origins in short fiction are still visible though no segment or chapter is wholly independent of the others. The majority of the stories are narrated by the novel's central protagonist, Mark Renton.
Each character narrates differently, in a fashion comparable to stream-of-consciousness or representative of psychological realism. For example, Spud will refer to people internally as "cats" (Begbie is a jungle cat, while he himself is a house cat), and Sick Boy will occasionally entertain an inner-dialogue between himself and Sean Connery. Chapters narrated by Renton are written with Scots dialect terms spelled phonetically to better convey the character's accent and pronunciation to an audience acquainted with Standard English, while Davie's chapters ("Bad Blood", "Traditional Sunday Breakfast") are narrated in Scottish English with dialect also appearing phonetically. Other chapters are written from a third-person omniscient stance (in Standard English) to cover the actions and thoughts of different characters simultaneously. For example, "The First Shag in Ages" covers Spud and Renton's outing to a nightclub where they meet Dianne and her pal, followed by Renton's return to Dianne's and the awkward breakfast that ensues, all the while revealing what each character thinks of the other.
Unlike the film it inspired, the novel's plot follows a nonlinear narrative. Characters are often introduced without backstory and without any initially obvious connection either to the core group of characters or to the junkie and lazy lifestyle.