This article examines the existence, description, perception, treatment, and outcome of symptoms consistent with autistic disorder in nineteenth-century London, England, based on case histories from the notes of Dr William Howship Dickinson at Great Ormond Street Hospital for Children. Three cases meeting the DSM-IV criteria for autistic disorder are described in detail. Other cases in which autistic traits are described are briefly summarized. The article explores the environment of contemporary medical practice, beliefs about childhood brain disorders, and social practice regarding children with brain disorders, and the impact of these factors on assessment and treatment. It correlates Dickinson's observations with current research on autism, providing information about children with autism before the condition was formally named in 1943.