Anorexia nervosa (AN) is primarily a mental disorder, characterised in modern society by disturbed attitudes towards weight, body shape and calorie balance. In earlier eras, anorexia did exist but religious or other values, rather than body image concerns, underlaid the obsessive-compulsive features. Serious physical and psychological complications cause high levels of disability and mortality. Early psychological intervention improves outcomes, but 20% develop severe and enduring symptoms and it has the highest mortality rate of any psychiatric disorder. AN has a biological component and shares significant genetic and neural network abnormalities with other mental illnesses, especially with obsessive-compulsive disorder (OCD). Functional neurosurgery, including stereotactic ablation (SA) and deep brain stimulation (DBS), are low-risk interventions that disrupt abnormal synchronised activity in neural circuits. Primarily used in movement disorders, these interventions are increasingly used in mental disorders, with evidence of efficacy from multiple randomised controlled trials in OCD and Gilles de la Tourette syndrome. Open-label studies of SA and DBS for AN report a large positive effect size on core psychopathology, quality of life and body mass index, sustained over many years. Early comorbid OCD symptoms and restricting AN subtype may be good prognostic predictors of response. Several surgical, psychological, logistical and financial factors may favour SA over DBS. However, the available evidence is limited and further studies are required to determine patient perception of, selection for and response to neurosurgery. AN is a potentially rewarding area for greater collaboration between eating disorders experts and functional neurosurgeons and offers hope to severely affected patients who have run out of treatment options.