Recognition of psychiatric disturbance and rate of referral to psychiatric units in general hospitals falls far short of the prevalence of psychiatric morbidity in such hospitals. This study has sought to determine whether particular patterns of "illness behaviour" contribute to the decision to refer. A group of patients referred to a psychiatric service was compared to a group of non-referred patients using the General Health Questionnaire (GHQ) as a general measure of morbidity, the Inventory to Diagnose Depression (IDD), the State-Trait Anxiety Inventory (STAI) and the Illness Behaviour Questionnaire (IBQ). The rate of referral to the service was 2.9% The estimated prevalence of psychiatric morbidity was 30% Referred patients scored more highly on all measures of morbidity (GHQ, IDD, STAI) and on the IBQ scale Affective Disturbance, and scored lower on the Denial Scale. Data are reported which suggest that patients with a strong somatic focus are less likely to be referred for psychiatric assessment despite the presence of significant psychiatric morbidity. The implications for health care delivery and identification of psychiatric morbidity are discussed.