The aim of this study was to examine the prevalence of psychiatric morbidity in a sample of medical and surgical inpatients in an Australian general hospital. Using the 60-item General Health Questionnaire, the estimated prevalence was 30% (previous studies have yielded estimates generally between 20 and 50%). The prevalence of morbidity was significantly higher in medical (45%) than in surgical (23%) inpatients. Twelve percent of patients (20% of medical patients and 8% of surgical patients) satisfied DSM-III criteria for a current Major Depressive Episode. Anxiety scores on the State-Trait Anxiety Inventory were higher than those reported in general population samples. There were no significant differences between males and females on any scores. The problems associated with the definition and identification of depressive and anxiety syndromes in medical and surgical inpatients are discussed, whilst the importance of this task is emphasized.