AJ Cronin (1896-1981) was a Scottish-born doctor-turned-novelist whose most famous novel is The Citadel, published in 1937. The book describes the struggles of an idealistic young doctor working in Wales and London in the 1920s and 30s. The novel was a global bestseller and its portrayal of a largely ineffective, corruption-ridden system of healthcare is thought to have directly influenced the foundation of the National Health Service in 1948. The Citadel anticipates such phenomena as evidence-based medicine and continuing medical education. This paper argues that the novel was never intended as propaganda for a state-controlled national health service. On the contrary, Cronin was against state control. Analysis of the novel is informed by recent biographical revelations about Cronin and the blurring of the margin between fact and fiction in Cronin's life and work is examined.