We here review Babylonian descriptions of neurological and psychiatric disorders, including epilepsy, stroke, psychoses, obsessive compulsive disorder, phobias, psychopathic behaviour, depression and anxiety. Most of these accounts date from the first Babylonian dynasty of the first half of the second millennium BC, within a millennium and a half of the origin of writing. The Babylonians were remarkably acute and objective observers of medical disorders and human behaviour. Their detailed descriptions are surprisingly similar to modern 19th and 20th century AD textbook accounts, with the exception of subjective thoughts and feelings which are more modern fields of enquiry. They had no knowledge of brain or psychological function. Some neuropsychiatric disorders, e.g. stroke or facial palsy, had a physical basis requiring the attention of a physician or asû, using a plant and mineral based pharmacology; some disorders such as epilepsy, psychoses, depression and anxiety were regarded as supernatural due to evil demons or spirits, or the anger of personal gods, and thus required the intervention of the priest or ašipu; other disorders such as obsessive compulsive disorder and psychopathic behaviour were regarded as a mystery. The Babylonians were the first to describe the clinical foundations of neurology and psychiatry. We discuss these accounts in relation to subsequent and more modern clinical descriptions.