One hundred and thirty-three female patients admitted to a neurological ward were fully investigated for the presence of organic neurological disease, and assessed for psychiatric disorder and illness behaviour, using the Clinical Interview Schedule (CIS) and the Illness Behaviour Questionnaire (IBQ). The likelihood of the presenting symptoms being due to organic disease was expressed by the neurologists on a visual analogue scale and the psychiatrists used a similar technique to describe whether the symptoms could be the result of psychiatric disorder. Many patients either had clear organic disease or somatic presentation of psychiatric disorder 'somatization', but one-third fell between these two extremes and either had a complex mixture of the two types of illness or could not be accurately diagnosed. The IBQ scores were raised in those with psychiatric disorder but did not help to explain why some patients present to the neurologists with symptoms that are unexplained by either organic disease or psychiatric disorder. Close liaison between neurologists and psychiatrists increases the detection of psychiatric disorder but some patients would require long-term follow-up to understand the true nature of the underlying disorder.