We propose the concept that anorexia nervosa is a neuropsychiatric developmental disorder. In support of the concept we present a case report of a 12-year-old girl with high functioning autistic disorder who developed Tourette syndrome and obsessive-compulsive disorder. She subsequently experienced a distinct onset of partial anorexia nervosa characterized by fear of gaining weight, body image distortions, food preference idiosyncrasies including avoidance of fat, dietary restriction, a pursuit of thinness, episodic self-induced vomiting, the missing of her menstrual cycles, and a 10% decrement in expected weight for height. She fell short of the required 15% decrement in expected weight for height to qualify for the full syndrome. Our case presentation emphasizes the longitudinal commonalities and symptomatic overlap of her multiple comorbidities. We discuss treatment approaches typically used with individuals with neuropsychiatric developmental disorders which might benefit higher functioning individuals with eating disorders. We conclude with examples of a neuropsychiatric developmental approach to generate a research agenda for anorexia nervosa.